Zika virus disease is caused by the Zika virus. For most people, it causes a very mild infection and no long-term problems. However, it may be harmful in pregnancy as it can lead to complications and birth defects in the baby. In particular, abnormally small heads (microcephaly).

Yellow fever is a serious viral infection that is spread by certain types of mosquito. It’s mainly found in sub-Saharan Africa, South America and parts of the Caribbean.

The womb (uterus) is a pear-shaped organ where a baby is carried during pregnancy. It is low in the pelvis (the area between the hips) and is supported by the pelvic floor muscles. Most womb cancers start in glandular cells found in the lining of the womb (the endometrium). They are called endometrial cancers. There are different types of endometrial cancers.

Wolff-Parkinson-White syndrome is a heart condition that affects the heart’s rhythm. It does not always cause symptoms but in some cases it can cause the heart to suddenly beat abnormally fast. Episodes can last from seconds to hours. In rare cases, episodes may continue for days.

Whooping cough, also called pertussis, is a highly contagious bacterial infection of the lungs and airways.

Whiplash happens when your head is suddenly jolted backwards and forwards in a whip like movement. This can irritate some of the muscles and ligaments in your neck. There is often a delay of 24-48 hours before you feel any pain or stiffness from whiplash.

Warts are small lumps that often develop on the skin of the hands and feet. They vary in appearance and may develop singly or in clusters. Most people will have warts at some point in their life. They tend to affect children and teenagers more than adults.

Vitamin B12 or B9 (commonly called folate) deficiency anaemia occurs when a lack of vitamin B12 or folate causes the body to produce abnormally large red blood cells that can’t function properly.

Vertigo is a symptom, rather than a condition itself. It’s the feeling that you, or the environment around you, is moving or spinning. This feeling may be barely noticeable, or it may be so severe that you find it difficult to keep your balance and do everyday tasks. Vertigo can develop suddenly and last for a few seconds or much longer. If you have severe vertigo, your symptoms may be constant and last for several days, making daily life very difficult.

A leg ulcer is a long-lasting (chronic) sore. They usually develop on the inside of the leg, just above the ankle.

Dementia is an umbrella term for a range of diseases that affect different brain functions, including memory. Vascular dementia is a common type of dementia. It’s caused by reduced blood flow to the brain.

Varicose eczema is a long-term skin condition that affects the lower legs and is common in people with varicose veins. It is also known as venous eczema, gravitational eczema and stasis eczema.

The main symptom of hives (urticaria) is a rash. The rash may: be raised be very itchy be on one part of the body spread over large areas range is size from a few millimetres to the size of a hand change in appearance within 24 hours

Urinary tract infections (UTIs) are common infections that affect the bladder, the kidneys and the tubes connected to them. A UTI can be painful and uncomfortable, but usually passes within a few days and can be treated with antibiotics.

Urinary incontinence is when you pee by accident. It can happen when doing exercise like running, lifting weights at the gym or jumping on a trampoline. Urinary incontinence can affect anyone. It tends to be more common in women.

An underactive thyroid gland (hypothyroidism) is where your thyroid gland doesn’t produce enough hormones. Common signs of an underactive thyroid are tiredness, weight gain and feeling depressed.

Ulcerative colitis is a long-term condition where your large bowel (colon and rectum) gets swollen and inflamed. Your colon is your large intestine (bowel). Your rectum is the end of your bowel, where poo is stored. If you have ulcerative colitis, you get swelling, inflammation and ulcers in the lining of your large bowel. They can bleed and produce pus.

Type 2 diabetes is a common health condition that can cause high blood sugar. With type 2 diabetes, either the pancreas doesn’t make enough insulin, or the insulin made doesn’t work correctly. Both of these means sugar stays in the blood instead of going into cells for energy.

Type 1 diabetes is a lifelong condition that causes a person’s blood glucose (sugar) level to become too high. This can make you feel unwell in the short term and can, over time, seriously damage your organs. Type 1 diabetes happens because the pancreas doesn’t produce insulin. Insulin is the hormone responsible for controlling the amount of glucose in your blood.

Tuberculosis (TB) is a bacterial infection spread through inhaling tiny droplets from the coughs or sneezes of an infected person. It is a serious condition, but can be cured with proper treatment.

Trigeminal neuralgia is a sudden, severe facial pain, described as sharp, shooting or like an electric shock. It usually occurs in sudden short attacks lasting from a few seconds to about two minutes, which stop just as abruptly.

Trichomonas is a sexually transmitted infection (STI) caused by a small parasite. It infects the genitals and may lead to an infection in the urethra (the tube that carries urine out of the body) and the prostate.

Transverse myelitis is a rare neurological condition. It’s caused by inflammation (swelling) of the spinal cord. The swelling damages the nerves and can leave permanent scars or lesions.

A transient ischaemic attack (TIA), or mini stroke, happens when there’s a temporary disruption in the blood supply to part of the brain. The disruption in blood supply results in a lack of oxygen to the brain. This can cause sudden symptoms like those of a stroke.

Tourette’s syndrome is a neurological condition that causes you to make involuntary movements and sounds called tics.

Toothache is pain in and around the teeth and jaws. It’s usually caused by tooth decay. You can feel toothache in many ways. It can come and go or be constant. Eating or drinking can make the pain worse, particularly if the food or drink is hot or cold.

Tooth decay can occur when acid is produced by plaque, which builds up on your teeth. This causes holes or cavities in teeth (dental caries). If untreated, decay progresses and can cause abscesses (collections of pus at the end of the teeth or in the gums). Plaque is also involved in gum disease.

Tonsillitis is an infection that causes inflammation (redness and swelling) of the tonsils. Tonsillitis is a common condition in children, teenagers and young adults.

Tinnitus is the name for hearing sounds that come from inside your body rather than an outside source. It’s not usually a sign of anything serious and may get better by itself.

Ticks are small, spider-like creatures. They feed on the blood of birds and mammals, including humans. Ticks vary in size and are usually between 1mm to 1cm long. They have either 6 or 8 legs.

The thyroid is a small gland in the front of your neck, just below your voicebox (larynx). The thyroid gland is part of the endocrine system. This system makes hormones that help control the way your body functions.

Your thumb injury may be referred to as a fracture, break or crack. These terms all mean the same thing. When you have a fracture, it’s not just the bone that’s affected. You’ll also have injured some of the soft tissues around it. Soft tissues include the: muscles ligaments tendons nerves.

Thrush is a very common yeast infection. It’s not a sexually transmitted infection (STI). It’s usually harmless but it can be uncomfortable and keep coming back.

Threadworms (pinworms) are tiny worms in your poo. They’re common in children and are spread easily. You may spot threadworms in your poo. The worms look like threads of white cotton and are about 1cm long.

Testicular cancer starts in one of the testicles. The testicles are the main part of the male reproductive system.

Tennis elbow is a condition which causes pain around the outside bony part of the elbow and down into the forearm. It’s also known as lateral epicondylitis or lateral epicondyle tendinopathy.

Syphilis is a bacterial infection. It’s hard to detect and is one of the most easily caught sexually transmitted infections (STIs).

Swollen lymph glands are usually a sign of infection. Swollen lymph glands that are caused by an infection usually get better by themselves in 1 to 2 weeks. Sometimes swollen lymph glands can have a more serious cause and may need to be seen by a doctor.

Supraventricular tachycardia is a condition where the heartbeat is abnormally fast. It can happen to anyone at any age and often occurs for the first time in children or young adults. In most cases, supraventricular tachycardia is harmless. It doesn’t usually last long and can settle without treatment.

Sunburn is skin damage caused by ultraviolet (UV) rays. It usually causes the skin to become red, sore, warm, tender and occasionally itchy for about a week.

Sudden arrhythmic death syndrome (SADS) is when someone dies suddenly and unexpectedly from a cardiac arrest but there’s no clear cause.

Subacromial pain syndrome is a general term used to describe pain which originates from the shoulder and can spread towards the neck or down the arm. It’s the most common reason for shoulder pain.

A stroke is a serious, life-threatening medical condition. It happens when the blood supply to part of the brain is cut off or if there’s bleeding within the brain. Strokes are a medical emergency and urgent treatment is essential. The sooner a person receives treatment for a stroke, the less damage to the brain is likely to occur.

Stomach ulcers (gastric ulcers) are open sores that develop on the lining of the stomach. Ulcers can also occur in part of the intestine just beyond the stomach. These are called duodenal ulcers. Stomach and duodenal ulcers are sometimes called peptic ulcers. This information applies to both.

The stomach is a stretchy, muscular bag that stores food and helps break it down through digestion. It is in the upper left-hand side of the tummy area (abdomen). Cancer can develop in the stomach. This is called stomach cancer or sometimes gastric cancer. Stomach cancer may spread to other parts of the body and can spread to lymph nodes close to the stomach.

Stomach aches are cramps or dull aches in the tummy (abdomen). Most stomach aches do not usually last long and are often not serious. Severe abdominal pain can be more serious.

Spinal stenosis is narrowing of the tunnels in the spine which contain the nerves or spinal cord. It’s a common condition. Most narrowing is a normal part of the ageing process and often does not cause problems.

Spina bifida is when a baby’s spinal column and spinal cord doesn’t form properly in the womb. This causes a gap or split in the spine. This causes damage to the central nervous system.

Sore throats are very common and usually nothing to worry about. They normally get better within a week. Most are caused by minor illnesses such as cold or flu and can be treated at home.

A soft tissue sarcoma (STS) is a rare cancer. It can develop in the cells of tissues that support, connect, surround and protect the organs in the body. These tissues include: fat muscle nerves fibrous tissues tendons and ligaments blood vessels.

Social anxiety disorder, also called social phobia, is a long-term and overwhelming fear of social situations. People with social anxiety disorder feel overly worried before, during and after social situations.

Slapped cheek syndrome (also called fifth disease or parvovirus B19) is a viral infection. It’s most common in children but it can affect people of any age. It usually causes a bright red rash on the cheeks.

Skin light sensitivity (photosensitivity) means you have an unusual reaction to light. This can cause symptoms like pain, redness, itching or a rash when the skin is exposed to light. These symptoms can range from very mild to very severe.

Melanoma, also called malignant melanoma, is a cancer that usually starts in the skin. It can start in a mole or in normal-looking skin.

Sjögren’s (pronounced Show-grin’s) syndrome is an autoimmune disorder. The body’s immune system attacks glands that secrete fluid, such as the tear and saliva glands.

Sinusitis is inflammation (redness and swelling) of the sinuses. The sinuses are small, air-filled spaces in your cheekbones and forehead. Inflammation blocks the sinuses so mucus cannot drain into your nose as usual.

Sickle cell disease is the name for a group of blood disorders. The most severe is sickle cell anaemia. These disorders are inherited, meaning they are passed on through your genes.

It’s normal to get out of breath when you’ve overexerted yourself. But when breathlessness comes on suddenly and unexpectedly, it’s usually a sign of a medical condition.

Shingles, also known as herpes zoster, is an infection of a nerve and the skin around it. It’s caused by the varicella-zoster virus, which also causes chickenpox.

Shigella is a bowel infection that can cause severe diarrhoea. It’s caused by bacteria called shigella. Shigella bacteria is most commonly found in faeces (poo). It’s usually caused by food contamination.

Septic shock is a life-threatening condition that happens when your blood pressure drops to a dangerously low level after an infection. Any type of bacteria can cause the infection. Fungi such as candida and viruses can also be a cause, although this is rare.

Sepsis is a serious complication of an infection. Without quick treatment, sepsis can lead to multiple organ failure and death.

Sciatica is a common condition and can also be known as nerve root or radicular pain. Sciatica is a term used to describe pain felt in the leg but which often comes from the lower back.

Schizophrenia is a serious mental health condition. It causes a range of different psychological symptoms. People experience symptoms of schizophrenia in different ways. They may start suddenly or develop slowly over time.

Scarlet fever is a bacterial illness that mainly affects children. It causes a distinctive pink-red rash. The illness is caused by Streptococcus pyogenes bacteria, also known as Group A Streptococcus, which are found on the skin and in the throat.

Scabies is a contagious skin condition caused by tiny mites that burrow into the skin. The main symptoms of scabies are intense itching and a rash in areas of the body where the mites have burrowed. The itching is often worse at night when your skin is warmer.

Rosacea is a common long-term skin condition that mainly affects the face. It can cause redness (blushing) on the cheeks, forehead, nose, chest and neck, as well as other symptoms.

Ringworm is a common fungal infection that can cause a red or silvery ring-like rash on the skin. Ringworm commonly affects arms and legs, but it can appear almost anywhere on the body. Despite its name, ringworm doesn’t have anything to do with worms.

Rheumatoid arthritis is a long-term condition. It can cause: pain swelling stiffness in the joints It can also cause deformity of the joints. It normally affects the hands, wrists and feet. But, other joints and parts of the body are sometimes also affected.

Respiratory syncytial virus (RSV) is a virus that can affect the lungs and airways. In most people, RSV causes mild cold-like symptoms. Occasionally, RSV can cause severe lung infections. These can include: bronchiolitis (an infection of the small airways in the lungs) pneumonia.

Restless legs syndrome (RLS), also known as Willis-Ekbom disease, is a common condition of the nervous system. It causes an overwhelming, irresistible urge to move the legs. As many as 1 in 10 people are affected by restless legs syndrome at some point in their life.

Reactive arthritis causes inflammation (redness and swelling) in different parts of the body. It usually develops after an infection. In most cases it clears up in a few months without causing long-term problems. Reactive arthritis can occur at any age, but it often affects young adults aged between 20 to 40. Men are generally affected more than women.

Raynaud’s phenomenon is a common condition that affects the blood supply to certain parts of the body – usually the fingers and toes. It’s often referred to as Raynaud’s syndrome, Raynaud’s disease or just Raynaud’s.

A phobia is a common type of anxiety disorder. Many people are afraid of things. Fear only becomes a phobia when you begin to organise your life around avoiding your fear.

Pulmonary hypertension is high pressure inside the pulmonary arteries, which are the vessels carrying blood from the right-hand side of the heart to the lungs.

The main symptoms of psychosis are: hallucinations – you might see, hear, feel, taste, or smell things that aren’t real, or you might hear voices delusions – you might believe things that are untrue, often this can lead someone to believe that someone is trying to harm them disordered thinking or speaking – you might speak more quickly or constantly, or switch from one topic to another mid-sentence These symptoms often occur together in what is known as a psychotic episode.

Psoriatic arthritis is a type of arthritis that sometimes develops in people with the skin condition psoriasis. It affects the joints and can cause them to become swollen, stiff and painful. It is estimated that around 1 in 4 patients with psoriasis have psoriatic arthritis.

Psoriasis is a skin condition that causes red, flaky, crusty patches of skin covered with silvery scales. These patches normally appear on your elbows, knees, scalp and lower back, but can appear anywhere on your body. Most people are only affected with small patches. In some cases, the patches can be itchy or sore.

Prostate cancer starts in the cells of the prostate. The prostate is a small gland that is just below the bladder and in front of the rectum (back passage).

Progressive supranuclear palsy (PSP) is a neurological condition. It’s caused by the loss of nerve cells in parts of the brain. This can lead to problems with balance, movement, vision, speech and swallowing.

Pressure ulcers are areas of damage to the skin and the tissue underneath. This happens when an area of skin is put under pressure. Pressure ulcers can also be known as pressure sores or bed sores.

Postnatal depression is a type of depression that many parents experience after having a baby. It affects more than 1 in 10 mothers within a year of giving birth. It can also affect fathers, although this is less common. With the right support, which can include self-help strategies and therapy, most people make a full recovery.

Postural orthostatic tachycardia syndrome (PoTS) is when your heart rate increases very quickly after getting up from sitting or lying down. Symptoms may ease with changes to your daily routine. Some people may need treatment with medicines.

Post-traumatic stress disorder (PTSD) is a mental health problem caused by traumatic events. PTSD can cause symptoms like problems sleeping, flashbacks and difficulty concentrating. This can have a big impact on your day-to-day life.

Post-polio syndrome is a slow progressive condition that affects some people that have had polio. It’s not life threatening but it can cause problems in your ability to carry out daily activities.

Post-concussion syndrome (PCS) describes a set of symptoms that sometimes happen after a concussion. They can last for several weeks or months.

Polymyalgia rheumatica is a condition that causes pain, stiffness and inflammation. This is mostly around the shoulders, neck and hips.

Polycystic ovary syndrome (PCOS) is a condition that affects how your ovaries work. Despite the name, there are no cysts on the ovaries. During ovulation, an egg is released once a month. PCOS can have an impact on this and cause irregular ovulation, or no ovulation at all. If you want to have a family, PCOS can make it difficult to get pregnant.

Polio is a serious viral infection and rare nowadays because it can be prevented with vaccination.

Pneumonia is inflammation of the lung tissue. It’s usually caused by a bacterial infection. There are clusters of tiny air sacs in your lungs. If you have pneumonia, these tiny sacs become inflamed and fill up with fluid.

Pleurisy is inflammation of the layers that cover the lungs (the pleura). It causes sharp chest pain (pleuritic pain) that gets worse when breathing or coughing.

Perthes’ disease, also known as Legg-Calvé-Perthes disease, is a rare childhood condition that affects the hip joint. The blood supply to the ball in the ball and socket joint (the femoral head) is disrupted for a short time. This causes the bone to soften and change shape. This process is called avascular necrosis.

Peripheral neuropathy develops when the peripheral nerves are damaged. The symptoms experienced depend on which nerves are affected.

Penile cancer is also known as cancer of the penis. Penile cancer is rare. Almost all cancers of the penis are squamous cell cancers. Squamous cells are found in the skin. They cover the surface of most parts of the body.

Pelvic organ prolapse is when one or more of the pelvic organs (your womb, bladder or bowel) slip from their usual position. This causes the vaginal wall to bulge into, or out of, the vagina.

Pelvic inflammatory disease (PID) is a bacterial infection. It affects the female reproductive system including the womb, fallopian tubes and ovaries.

Patellofemoral pain syndrome is a condition that causes pain behind or around the kneecap. It’s a leading cause of chronic knee pain, which 1 in 3 adults may experience at some point in their life. 

Patau’s syndrome, also known as Trisomy 13, is a rare but serious genetic condition. It begins to affect babies when they’re in the womb, and will continue to cause health problems throughout their life.

Parkinson’s disease is a condition in which parts of the brain become progressively damaged over many years. The three main symptoms of Parkinson’s disease are: involuntary shaking of particular parts of the body (tremor) slow movement stiff and inflexible muscles.

Panic disorder is where you keep having panic attacks, often for no obvious reason. Everyone experiences feelings of anxiety and panic at certain times during their lifetime. It’s a natural response to stressful or dangerous situations.

Pancreatic cancer is a cancer that starts in the pancreas. The pancreas is part of the digestive system. The pancreas makes digestive juices called enzymes. It also makes hormones including insulin.

Overactive thyroid (also known as hyperthyroidism) is a relatively common hormonal condition that occurs when there is too much thyroid hormone in the body.

An ovarian cyst is a fluid-filled sac that develops on an ovary. They’re very common and do not usually cause any symptoms. Most ovarian cysts are generally harmless and disappear without treatment in a few months.

The ovaries are 2 small, oval-shaped organs in the pelvis (lower area between the hips). They are on either side of the womb (uterus), close to the fallopian tubes. These link the ovaries to the womb. A layer of tissue called the peritoneum supports the ovaries.

Otitis externa is an infection that causes inflammation (redness and swelling) of the ear canal, which is the tube between the outer ear and the eardrum. Otitis externa is often called ‘swimmer’s ear’ because regularly getting water in your ear can make inflammation more likely.

Osteoporosis is a condition where bones have become less dense (thinner). This makes them fragile and more likely to break. It develops slowly over several years. It’s often only diagnosed when a minor fall or sudden impact causes a bone to fracture or break.

Osteoarthritis is a condition that causes the joints to become painful and stiff. The main symptoms of osteoarthritis are pain and stiffness in your joints. This can make it difficult to move the affected joints and do certain activities.

Oral thrush is a fungal infection of the mouth. It’s not contagious and is usually successfully treated with antifungal medication. It’s also called oral candidosis (or candiasis) because it’s caused by a group of yeasts called Candida.

The oesophagus (gullet) is part of the digestive system, which is sometimes called the gastro-intestinal or GI tract. The oesophagus is a muscular tube that goes from the mouth down through the chest to the stomach.

Oculopharyngeal muscular dystrophy (OPMD) affects the muscles in the eyes (ocular) and the throat (pharyngeal). Someone with OPMD will usually start to experience symptoms in their 40’s or 50’s.

Obstructive sleep apnoea (OSA) is a relatively common condition where the walls of the throat relax and narrow or close during sleep. This interrupts normal breathing. It may lead to regularly broken sleep which can: impact your quality of life – mainly by making you very sleepy during the day increase the risk of developing certain conditions.

Obsessive compulsive disorder (OCD) is a mental health condition. It causes you to have obsessive thoughts and carry out compulsive activity. This can be distressing and can have a big impact on your life. Treatment can help you keep it under control.

Obesity is a chronic condition. Having obesity means you have too much body fat which could cause risks to your health.

Nosebleeds are not usually a sign of anything serious. During a nosebleed, blood flows from one or both nostrils. It can be heavy or light. It can last from a few seconds to 15 minutes or more.

Norovirus causes diarrhoea and vomiting. Norovirus can be very unpleasant but usually clears up by itself in a few days.

Non-Hodgkin lymphoma (NHL) is a type of blood cancer. It develops when blood cells called lymphocytes become abnormal.

Non-alcoholic fatty liver disease (NAFLD) is the term for a range of conditions caused by a build-up of fat in the liver. It’s usually seen in people who are overweight or obese.

A neuroendocrine tumour (NET) is a tumour that develops from cells of the neuroendocrine system. Neuroendocrine cells are similar to nerve cells. They make chemical messengers called hormones. Hormones control how different organs in the body work.

A neck injury can be caused by smaller injuries such as a muscle strain or by a larger injury such as a fall from a height. You may have also hurt your head if you have had a neck injury.

Nasopharyngeal cancer is sometimes called nasopharyngeal carcinoma or cancer of the post-nasal space. It is a type of head and neck cancer that develops in the nasopharynx.

Nasal and sinus cancer are rare types of head and neck cancer that develop inside the nose or paranasal sinuses.

Myotonic dystrophy is a genetic condition that causes progressive muscle weakness and wasting. Myotonic dystrophy can affect muscles of movement and often affects the electrical conduction system of the heart, breathing and swallowing muscles, bowels, lens of the eye and brain.

Mycoplasma genitalium (Mgen) is a bacterial infection. It can affect the cervix, inside the penis (urethra) or the anus.

Myasthenia gravis is a long term (chronic) condition that causes muscle weakness and fatigue. It’s a rare condition that commonly affects the muscles that control the eyes and eyelids. It can also affect the face, speaking, chewing, swallowing and other parts of the body.

Muscular dystrophy (MD) refers to a group of inherited genetic muscle conditions. MD causes progressive muscle weakness and muscle wasting because of the degeneration (deterioration) of muscle cells.

Munchausen’s syndrome is a rare psychological and behavioural condition in which somebody fabricates or induces symptoms of illness in themselves.

Mumps is an infection that spreads easily. It used to be common in children before the introduction of the measles, mumps and rubella (MMR) vaccine.

Multiple system atrophy (MSA) is a neurological condition that affects adults. It’s caused by the degeneration (damage) or atrophy (shrinking) of nerve cells in different parts of the brain.

Multiple sclerosis (MS) is a condition that affects the brain and/or spinal cord. It can cause symptoms like problems with vision, arm or leg movement, sensation or balance.

Myeloma is a type of blood cancer that develops from abnormal (cancerous) plasma cells. Normal plasma cells are a type of white blood cell that fight infection. They are made in the bone marrow.

Mouth ulcers are painful sores that appear in the mouth. They’re uncomfortable but they’re usually harmless. Most clear up by themselves within 1 to 2 weeks.

Mouth cancer is also known as oral cancer. It is one of the most common types of head and neck cancer. It can start in any part of the mouth.

Motor neurone disease (MND) is a rare condition that progressively damages parts of the nervous system. This leads to muscle weakness, often with visible wasting. Amyotrophic lateral sclerosis (ALS) is the most common form of MND.

A miscarriage is the loss of a pregnancy before 24 weeks. About 1 in 5 pregnancies miscarry. Miscarriage symptoms can be varied. Some people have very clear symptoms, while others may experience none at all. Miscarriage signs can change, depending on whether you’re having an early miscarriage or a late miscarriage.

A minor head injury is an injury (like a bump or a cut) to the head that doesn’t result in any serious brain injury. Sometimes a minor head injury can cause concussion, but this is not always the case.

Migraine is a common health condition. It affects around 1 in 5 women and around 1 in 15 men. It usually begins in early adulthood. A migraine headache is usually a moderate or severe headache felt as a throbbing pain on one side of the head.

Mesothelioma is a cancer of the mesothelium. This is a thin lining (membrane) that covers the outer surface of many organs in the body. It also lines the spaces (cavities) within the body, such as the chest and abdominal cavity.

Ménière’s disease is a rare inner ear condition that can affect your balance and hearing. It cannot be cured, but treatments can usually help your symptoms.

Meningitis is an infection of the protective membranes that surround the brain and spinal cord (meninges).

Mechanical neck pain is a common problem. Two out of three of us will experience it at some point. It’s not usually serious and most often eases on its own. Healthcare professionals also sometimes call mechanical neck pain: simple neck pain non-specific neck pain.

Measles is a viral infection that spreads very easily. It’s unpleasant and can sometimes have serious complications. Having the measles, mumps and rubella (MMR) vaccine is the best way to prevent it.

Malnutrition means poor nutrition. Most commonly this is caused by not eating enough (undernutrition) or not eating enough of the right food to give your body the nutrients it needs.

Malaria is a serious tropical disease spread by mosquitoes. If it isn’t diagnosed and treated quickly, it can be fatal. A single mosquito bite is all it takes for someone to become infected.

Lymphoedema is a long-term condition that causes swelling in the body’s tissues. It can affect any part of the body, but usually develops in the arms or legs. Lymphoedema is caused by a problem with the lymphatic system. The lymphatic system is a group of vessels and glands around the body. It helps to fight infection and drain excess fluid from tissues.

Lyme disease is a bacterial infection spread to humans by infected ticks. It’s also known as Lyme borreliosis.

Lupus is a complex and poorly understood condition that affects many parts of the body and causes symptoms ranging from mild to life-threatening.

Cancer that starts in the lung is called primary lung cancer. The lungs are the parts of the body that we use to breathe. There are 2 main types of primary lung cancer. These are non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC).

The liver is the second largest organ in the body. It works hard, performing hundreds of complex functions, including: fighting infections and illness removing toxins (poisons), such as alcohol, from the body controlling cholesterol levels helping blood to clot (thicken) releasing bile, a liquid that breaks down fats and aids digestion Liver disease doesn’t usually cause any obvious signs or symptoms until it’s fairly advanced and the liver is damaged. At this stage, possible symptoms can include loss of appetite, weight loss and jaundice.

Liver cancer is a cancer that starts in the liver. It is sometimes called primary liver cancer. A cancer that starts somewhere else in the body and spreads to the liver is called secondary cancer in the liver.

Lipoedema is a long term (chronic) condition of fat and connective tissue which builds up in your legs, hips, bottom and sometimes arms. It affects both sides of the body equally.

Limb girdle muscular dystrophies (LGMD) are rare conditions. They present differently in everyone they affect, even those in the same family. LGMD causes weakness in the shoulder and pelvic girdle which includes the big muscles around the top (proximal) part of the arms and legs (hips, thigh and shoulder muscles).

Lichen planus is a non-infectious, itchy rash that can affect many areas of the body. Affected areas can include the: arms, legs and trunk mouth (oral lichen planus) nails and scalp vulva, vagina and penis.

Legionnaires’ disease is a severe form of pneumonia. It’s caused by Legionella bacteria. Infection can be spread by breathing in droplets of water from things like hot tubs or air conditioning.

Laryngitis is inflammation of the larynx (voice box). Symptoms of laryngitis can begin suddenly and usually get worse over a period of 2 to 3 days. Common symptoms of laryngitis include: hoarseness difficulty speaking sore throat mild fever irritating cough a constant need to clear your throat.

The larynx is also called the voice box. It’s in the neck, above the windpipe (trachea) and in front of the gullet (oesophagus). The larynx allows the air you breathe in to reach your lungs. It also contains the 2 vocal cords which vibrate together when air passes between them. This makes the sound of your voice.

Lactose intolerance is a common digestive problem where the body is unable to digest lactose, a type of sugar mainly found in milk and dairy products.

Labyrinthitis is an inner ear infection. It causes the labyrinth inside your ear to become inflamed, affecting your hearing and balance.

Kidney stones can develop in one or both kidneys. The medical term for kidney stones is nephrolithiasis, and if they cause severe pain it’s known as renal colic.

A kidney infection (pyelonephritis) is a painful and unpleasant illness caused by bacteria travelling from your bladder into one or both of your kidneys. It’s more serious than cystitis, a common infection of the bladder that makes urinating painful.

The kidneys are part of the urinary system. They filter waste from the blood and make pee. Kidney cancer is a disease where abnormal cells develop and grow in one of the kidneys. This forms a tumour.

Kaposi’s sarcoma (KS) is a type of soft tissue sarcoma that usually affects the: skin lining of the mouth. It rarely affects organs inside the body, such as the lungs, liver, stomach, bowel or lymph nodes. It can develop in several parts of the body at the same time.

Joint hypermobility means that some or all of a person’s joints have an unusually large range of movement. People with hypermobility are very supple. This means they’re able to move their limbs into positions others find impossible. Some people also refer to this as having loose joints or being double-jointed.

Irritable bowel syndrome (IBS) is a common, long-term condition of the digestive system. The condition is often lifelong, although the symptoms may change over time. With the right strategies, IBS can be successfully managed.

Iron deficiency anaemia is a condition where a lack of iron in the body leads to a reduction in the number of red blood cells. Iron is used to produce red blood cells, which help store and carry oxygen in the blood. If you have fewer red blood cells than is normal, your organs and tissues won’t get as much oxygen as they usually would.

Intoeing is when your child walks with their feet turned. Some call this hen-toeing or pigeon toeing. This is normal in childhood.

Insomnia can mean both: struggling to get to sleep difficulty staying asleep. If you have insomnia, you might: find it hard to fall asleep lie awake at night wake up several times during the night wake up early in the morning and not be able to get back to sleep not feel refreshed when you get up feel tired and irritable during the day have difficulty concentrating because you’re tired Sometimes episodes of insomnia can come and go without causing any serious problems. But, some people can have insomnia for months or even years at a time.

An ingrown toenail is a common problem where the nail grows into the skin around the nail. It can be painful but there are ways to manage the discomfort.

Indigestion can be pain or discomfort in your upper abdomen (dyspepsia) or burning pain behind the breastbone (heartburn). Dyspepsia and heartburn may occur together or on their own. Symptoms usually appear soon after eating or drinking.

Impetigo is a common and highly contagious skin infection that causes sores and blisters. It’s not usually serious and often improves within a week of treatment or within a few weeks without treatment.

Idiopathic pulmonary fibrosis (IPF) is where the lungs become scarred and breathing becomes more difficult. It’s not clear what causes it, but it usually affects people around 70 to 75 years old. It’s rare to develop in people under 50. The older you are, the more likely you are to develop IPF.

Hypothermia is when the body’s temperature drops below 35°C. Normal body temperature is 37°C. When your body temperature gets this low, less blood is circulated around your body and normal body functions start to slow down.

Hypoglycaemia, or a “hypo”, is an abnormally low level of glucose in your blood (less than four millimoles per litre). When your glucose (sugar) level is too low, your body doesn’t have enough energy to carry out its activities.

Hyperglycaemia (high blood sugar) can affect people with type 1 diabetes and type 2 diabetes, as well as pregnant women with gestational diabetes. It can occasionally affect people who don’t have diabetes.

Hydrocephalus is a condition that causes a build up of fluid in the brain. The excess fluid affects the brain and how it functions.

Huntington’s disease is a condition that damages nerve cells in the brain causing them to stop working properly. It’s passed on (inherited) from a person’s parents. The damage to the brain gets worse over time. It can affect movement, cognition (perception, awareness, thinking, judgement) and mental health.

Hodgkin lymphoma (HL) is a type of blood cancer. It develops when blood cells called lymphocytes become abnormal.

HIV is a long-term health condition. HIV stands for human immunodeficiency virus. The virus targets the immune system and if untreated, weakens your ability to fight infections and disease.

Cholesterol is a fatty substance that’s produced in the liver. It’s also in some foods that we eat. The body needs a certain amount of cholesterol to function normally. Cholesterol combines with proteins to be carried around the blood. This combination is known as lipoproteins.

Blood pressure is the pressure of blood in the arteries. The arteries are vessels that carry blood from the heart around the body. There needs to be a certain level of pressure in the arteries to move blood around the body. But, if blood pressure is higher than recommended over time it increases the risk of cardiovascular diseases like stroke or heart attack.

A hiatus hernia, or hiatal hernia, is when part of the stomach squeezes up into the chest through an opening (‘hiatus’) in the diaphragm. The diaphragm is a large, thin sheet of muscle between the chest and the abdomen (tummy).

Hepatitis C is a liver infection that’s spread through blood. It can be cured with treatment. But if left untreated, it can sometimes cause serious and potentially life-threatening damage to the liver over many years.

Hepatitis B is a liver infection that’s spread through blood and body fluids.

Hepatitis A is a liver infection that’s spread in the poo of an infected person. Hepatitis A is not usually serious. Most people get better within a couple of months.

Heat illness such as heatstroke happens in hot places, both indoors and outdoors. It can be caused by being active in a place that’s too hot. Heat illness can range from mild to severe, and heat exhaustion and heatstroke are the most serious types.

Palpitation is an awareness of your heartbeat. For example, your heart might feel like it’s pounding, fluttering or beating irregularly. This is often just for a few seconds or minutes. You may feel these sensations in your chest, throat or neck.

Heart failure is a condition where your heart cannot pump blood around your body as well as it should. It does not mean that your heart has stopped working completely, but you may need support to help it to work better and to manage your symptoms.

A heart attack happens when there’s a reduction in blood supply to part of the heart muscle. This lack of blood flow can cause damage to the heart.

Hearing loss is a common problem that often develops with age or is caused by repeated exposure to loud noises.

Most headaches are not serious. In many cases, you can treat your headache at home.

Head lice are tiny insects that live in hair. Nits are the empty egg cases attached to hair that head lice hatch from.

Head and neck cancer is a general term to describe different cancers in this area. These cancers start in the tissues in the head and neck area. For example, in the: mouth which includes the tongue, palate, gums and lips throat (the pharynx) which is divided into the nasopharynx, oropharynx and hypopharynx nose and sinuses (air-filled spaces in the bones of the face) salivary glands which make saliva middle ear which contains the ear drum

Hay fever is a common allergic condition. You’ll experience hay fever symptoms if you have an allergic reaction to pollen which is released by plants.

Hand, foot and mouth disease is a common illness. It causes mouth ulcers and spots on the hands and feet. It’s most common in young children, particularly those under 10. But, it can affect older children and adults as well.

Haemorrhoids, also known as piles, are swellings containing enlarged blood vessels that are found inside or around the bottom (the rectum and anus).

Gum disease is a very common condition where the gums bleed, become swollen, sore or infected.

Greater trochanteric pain syndrome (GTPS), also known as lateral hip pain or trochanteric bursitis, is a common and painful condition which affects the outer side of the hip and thigh. It occurs when the tissues which lie over the outside of the hip bone (greater trochanter) become irritated.

Gout is a type of arthritis in which small crystals form inside and around the joints. It causes sudden flares of severe pain and swelling.

Gonorrhoea is a sexually transmitted infection caused by bacteria. Infection usually occurs in the genitals but can affect the throat, eyes and anus.

Golfer’s elbow is a condition which causes pain around the inside bony part of the elbow and down into the forearm. It’s also known as medial epicondylitis or medial epicondyle tendinopathy.

Glandular fever is a type of viral infection that mostly affects young adults. It normally gets better without treatment, but it can make you feel very ill. It normally lasts for 2 to 3 weeks, but in some cases you can feel ill for months. It can also be known as infectious mononucleosis, or ‘mono’.

Genital herpes is a sexually transmitted infection (STI) caused by a virus called herpes simplex virus (HSV). There are 2 different types of the virus. Both of which affect the genitals.

Anxiety is a feeling of unease, like worry or fear, that can be mild or severe. It’s the main symptom of several conditions, including: panic disorder phobias post-traumatic stress disorder (PTSD) social anxiety disorder (social phobia)

Gastro-oesophageal reflux disease (GORD) is a common condition, where acid from the stomach leaks up into the oesophagus (gullet).

Gastroenteritis is a very common condition that causes diarrhoea and vomiting. It’s usually caused by a bacterial or viral tummy bug.

Ganglion cysts are fluid-filled lumps that can change in size. The most common type of swelling is in the hand, wrist or foot. They tend to be smooth and round.

Gallstones are small stones, usually made of cholesterol, that form in the gallbladder. In most cases they don’t cause any symptoms and don’t need to be treated.

Gallbladder cancer is rare. It is most common in people over 75. The gallbladder is a small pouch that sits under the right side of the liver. It stores bile, a fluid made in the liver. Bile helps to digest food and break down fats.

A fungal nail infection is when the the nail becomes thick, discoloured and easy to break. It’s not a serious infection but it can take a long time to treat.

Functional neurological disorder (FND) describes a problem with how the brain receives and sends information to the rest of the body.

Frozen shoulder is a condition that leads to pain and stiffness of the shoulder. It’s also known as adhesive capsulitis or shoulder contracture.

A fragility fracture is a break in the bone from an impact or fall that would not normally be expected to cause a fracture.

Food poisoning is an illness caused by eating contaminated food. It’s not usually serious and most people get better within a few days without treatment.

A food allergy is when the body’s immune system reacts unusually to specific foods. Although allergic reactions are often mild, they can be very serious.

Flu (influenza) is a common infectious viral illness. You can catch flu all year round. This is why it’s also known as seasonal flu. You can catch flu many times because flu viruses change regularly. Your body won’t have a natural resistance to the new versions.

Fibromyalgia is a long-term condition that causes pain all over the body.

Fibroids are non-cancerous growths that develop in the muscular wall of the womb (uterus). These growths are made up of muscle and tissue and can be different sizes. Some can be the size of a pea, others can be the size of a melon. They’re sometimes known as uterine myomas or leiomyomas.

It can be extremely worrying if your child has a high temperature. But it’s very common and often clears up by itself without treatment. A quick and easy way to find out whether your child has a fever is to take their temperature using a thermometer.

A fever is usually when your body temperature is 38°C or higher. You may feel warm, cold or shivery.

Globus is a symptom that can make you feel like you have a lump in your throat. It’s also called ‘globus sensation’.

A febrile seizure is a convulsion (also known as a fit) that can happen when a child has a fever. Febrile seizures are also sometimes called febrile convulsions.

Facioscapulohumeral muscular dystrophy (FSHD) is one of the most common forms of MD. It affects all genders. Males are likely to experience more severe symptoms at an earlier stage.

Eye cancer is rare. There are different cancers that can affect the eye. Eye melanoma is the most common type. It is also called ocular melanoma.

Excessive sweating (hyperhidrosis) is common. It can develop at any age but often starts in childhood or puberty.

Ewing sarcoma is a type of primary bone cancer (also called bone sarcoma). Sarcomas are rare cancers that develop in the supporting tissues of the body. Supporting tissues include bone, cartilage, tendons, fat and muscle.

Escherichia coli O157, sometimes called STEC (Shiga toxin-producing Escherichia coli), is a bacterial infection. It can cause severe stomach pain, bloody diarrhoea and kidney failure.

Epilepsy is a condition that affects the brain and is defined by repeated seizures. The main symptoms of epilepsy are repeated seizures. There are different types of seizure, depending on which part of the brain it affects.

Endometriosis is a long-term (chronic) condition where tissue similar to the lining of the womb is found elsewhere in the body. It’s very common, affecting around 1 in 10 women or those assigned female at birth. For some people, it can have a significant impact on their lives.

The symptoms of Emery-Dreifuss muscular dystrophy (EDMD) often start to develop during childhood or teenage years. Like other types of muscular dystrophy (MD), it’s a muscle wasting disease.

Edwards’ syndrome (also known as trisomy 18) is a genetic condition that begins to affect babies when they’re in the womb, and continues to impact their health throughout their life. It’s a rare but serious condition.

Your injury may be referred to as a fracture, break or crack. These terms all mean the same thing. When you have a fracture, it’s not just the bone that’s affected. You’ll also have injured some of the soft tissues around it. Soft tissues include the: muscles ligaments tendons nerves

An ectopic pregnancy happens when a fertilised egg implants in the wrong place. An ectopic pregnancy is almost always unable to survive. Cases where an ectopic pregnancy survives have been reported, but they are exceptionally rare.

Ebola virus disease is a serious illness that originated in Africa, where a large outbreak occurred in 2014 to 2015. In June 2016, the outbreak was officially declared over.

Earwax is made inside your ears to keep them clean. It usually falls out on its own. Sometimes too much can build up and block the ears.

An early miscarriage is the loss of your pregnancy before the 12th week of pregnancy. This is the most common type of miscarriage.

Earache is a common problem, particularly in children. It can be worrying, but it’s usually only caused by a minor infection and will often get better in a few days without treatment.

Dystonia is a neurological movement disorder. People with dystonia experience involuntary muscle spasms and contractions.

Dysphagia is the medical term for swallowing difficulties. Some people with dysphagia have problems swallowing certain foods or liquids, while others can’t swallow at all.

Duchenne muscular dystrophy (DMD) is a muscle wasting condition that causes progressive muscle weakness. It usually only affects males.

It’s normal to occasionally have a dry mouth if you’re dehydrated or feeling nervous. A persistently dry mouth can be a sign of an underlying problem though.

Dizziness (lightheadedness) is a common symptom. It’s not usually a sign of anything serious but it should still be investigated by a doctor. Dizziness can mean different things to different people. Some people use it to describe feeling lightheaded or off balance. Others use it to describe a feeling that their surroundings are spinning.

Diverticular disease and diverticulitis are related digestive conditions that affect the large intestine (colon).

Discoid eczema (discoid dermatitis) is a long-term skin condition that usually affects adults. It causes itchy, cracked and red skin in a circular shape. It can affect any part of the skin.

Diarrhoea is passing looser, watery or more frequent poo (stools) than is normal for you. It affects most people from time to time. It can be distressing and unpleasant but is usually nothing to worry about. It normally clears up in a few days to a week.

Diabetic retinopathy is a complication of diabetes, caused by high blood sugar levels damaging the back of the eye (retina). It can cause blindness if left undiagnosed and untreated.

Having diabetes means you have a higher risk of developing issues with your feet. This is because having higher blood glucose levels for a long time can cause nerve damage (also called neuropathy) in your feet.

Dermatitis herpetiformis (DH) is an autoimmune skin condition that can be linked to coeliac disease.

Depression is a mental health condition that has a range of symptoms. These can affect how you think and feel. For example, you may feel low or lose enjoyment or interest in things. Symptoms of depression can range from mild to severe. How much depression impacts your day-to-day life will depend on how severe it is. It’s not always possible to tell that you have symptoms of depression right away. It can start and progress gradually.

A dental abscess is a collection of pus that can form inside the teeth, in the gums, or in the bone that holds the teeth in place. It’s caused by a bacterial infection. An abscess at the end of a tooth is called a periapical abscess. An abscess in the gum is called a periodontal abscess. Dental abscesses are often painful, but aren’t always. In either case, they should be looked at by a dentist.

Dementia is an an umbrella term for a range of diseases that affect different brain functions, including memory. Dementia with Lewy bodies is a common form of dementia. It’s also known as Lewy body dementia.

Dementia is an umbrella term for a range of conditions associated with damage to the brain or brain cells (neuron). This means the brain cannot work as well as it should. Dementia can affect your ability to remember, think and speak. It also affects how you feel and behave.

Delirium (acute confusional state) is when someone’s mental function has a sudden change. It comes on quickly, often over hours or days. As well as showing confusion, people with delirium can be sleepy, agitated, have altered beliefs or see hallucinations.

Dehydration is when your body loses more fluid than you take in. It can be serious if it isn’t treated. Drinking fluids (such as water, diluted squash or fruit juice) regularly can prevent dehydration.

Degenerative cervical myelopathy is a condition that is caused by age related changes to the bones, ligaments and discs of the neck. This can sometimes cause pressure on the spinal cord which can affect function of the nerves.

Deep vein thrombosis (DVT) is a blood clot that develops within a vein, usually in the leg. Swelling is one of the main symptoms of DVT. It may not always be easy to notice. Swelling can happen in any part of your leg, but usually happens in the back of the leg.

Deafblindness is a combination of sight and hearing loss that affects a person’s ability to communicate, access information and get around. It’s also sometimes called ‘dual sensory loss’ or ‘multi-sensory impairment’.

Cystitis is a type of urinary tract infection (UTI) that affects the bladder. It’s common, particularly in women. Cystitis often gets better by itself but may sometimes be treated with antibiotics.

Cystic fibrosis is an inherited condition in which the lungs and digestive system can become clogged with thick, sticky mucus.

Croup is a childhood condition that affects the windpipe (trachea), the airways to the lungs (the bronchi) and the voice box (larynx).

Crohn’s disease is a long-term condition that causes inflammation of the lining of the digestive system.

A cough is a reflex action to clear your airways of phlegm and irritants such as dust or smoke. It’s rarely a sign of anything serious.

Costochondritis is the medical term for inflammation of the cartilage that joins your ribs to your breastbone (sternum). Cartilage is tough but flexible connective tissue. It acts as a shock absorber, cushioning the joints.

Coronavirus, and other respiratory infections like flu, can spread easily and cause serious illness in some people.

Coronary heart disease (CHD) is a term used to describe what happens when the blood flow to the heart is interrupted or reduced. It is also known as ischaemic heart disease.

Constipation is a common condition that affects people of all ages. It can mean that you’re not passing stools regularly or you’re unable to completely empty your bowel.

Conjunctivitis (or red eye) is a common eye condition. It usually gets better in a few weeks without treatment.

The congenital muscular dystrophies (CMD) are a group of conditions normally present from birth, or in the first few months of life.

Congenital heart disease is a general term used to refer to a series of birth defects that affect the heart.

Concussion is a type of brain injury. It sometimes happens after a head injury, or a forceful knock to the body. It can happen even if you’ve stayed conscious (awake) after the injury. Only 10% of concussions involve someone being knocked out.

A cold is a very common mild viral infection. You can often treat a cold without seeing a GP. You should begin to feel better in about 1 to 2 weeks.

A coma is a state of unconsciousness where a person is unresponsive and cannot be woken. It can result from injury to the brain, like a severe head injury or stroke. There are also a range of conditions that can cause a coma. A patient may be placed into a coma while in the intensive care unit (ICU) as part of their treatment. This might be called an ‘induced coma’.

Cold sores are small blisters that develop on the lips or around the mouth. They’re caused by the herpes simplex virus (HSV). A cold sore will usually clear up without treatment within 7 to 10 days.

Coeliac disease is a common autoimmune condition where the immune system in a person’s intestine (gut) reacts when they eat gluten. This causes chronic inflammation.

Clostridium difficile, also known as C. difficile or C. diff, is a bacterium that can infect the bowel and cause diarrhoea.

When you have a fracture, it’s not just the bone that’s affected. You’ll also have injured some of the soft tissues around it. Soft tissues include the: muscles ligaments tendons nerves

Cirrhosis is scarring of the liver caused by continuous, long-term liver damage. Scar tissue replaces healthy tissue in the liver and prevents the liver from working properly.

Chronic obstructive pulmonary disease (COPD) is a collection of lung diseases. It includes chronic bronchitis, emphysema and chronic obstructive airways disease. People with COPD have difficulties breathing.

Chronic myeloid leukaemia (CML) is a cancer of the white blood cells. It starts to develop in blood stem cells in the bone marrow. It causes early white blood cells to become abnormal. CML usually develops very slowly.

Chronic lymphocytic leukaemia (also called CLL or CLL leukemia) is the most common type of leukaemia. Blood cells are made in the bone marrow. The bone marrow is a spongy material in the middle of our bones. All blood cells are made from blood stem cells. These are blood cells at the earliest stage of their development. The new, developing blood cells are called blast cells.

Chronic kidney disease (CKD) is a long-term condition where the kidneys do not work effectively. CKD does not usually cause symptoms until it reaches an advanced stage.

Chronic fatigue syndrome (CFS) is a long term (chronic) neurological condition. It affects many body systems, most commonly, the nervous and immune systems.

Chlamydia is a bacterial infection. Most people with chlamydia don’t notice any symptoms and don’t know they have it. So it’s important to get tested if you think you’re infected.

Chilblains are small, itchy swellings on the skin that can appear after you’ve been in the cold. Chilblains can be uncomfortable, but they usually get better on their own within a few weeks.

Chickenpox (known medically as varicella) is caused by a virus called the varicella-zoster virus. It’s spread quickly and easily from someone who is infected.

Chest infections are common, especially after a cold or flu. Although most are mild and get better on their own, some can be serious or even life-threatening.

Cervical spondylosis is a medical term for age -related changes in the neck. It’s also known as neck osteoarthritis. As we get older, it is normal to have some age-related changes in our neck. Often this occurs with no symptoms.

Cervical cancer develops very slowly from abnormal cell changes in the cervix. These changes do not cause any symptoms, but they may be found with cervical screening tests. If the tests show abnormal cell changes, treatment can prevent cancer developing.

Cerebral palsy is a condition caused by either damage to the brain, or abnormal development of the brain. This damage normally occurs before birth or during a child’s early development. Cerebral palsy is not normally progressive in nature.

Cellulitis is an infection of the deeper layers of skin and underlying tissue. It can be serious if it’s not treated quickly.

Catarrh is a build-up of mucus (phlegm) in your airways. It usually affects the back of the nose, the throat or the sinuses. It’s often temporary, but some people experience it for months or years. This is known as chronic catarrh.

Carpal tunnel syndrome is a common condition affecting the median nerve as it passes through a narrow tunnel in the wrist.  The carpal tunnel is made up of the bones of your wrist, called carpals, and a thick ligament. The tunnel contains the tendons that bend your fingers and thumb as well as the median nerve.

Cardiovascular disease (CVD) is a general term that includes diseases that affect the heart and blood vessels. This includes stroke and conditions that affect the heart. For example, heart attack, heart failure or heart rhythm problems.

Cardiac arrest is when the heart suddenly stops pumping blood around the body. This will cause a person to lose consciousness. Their breathing will be affected too. They will either stop breathing completely or stop breathing normally. This usually happens without warning.

A bunion (hallux valgus) is a deformity caused by the base joint of the big toe developing sideways. This pushes the bones of the big toe towards the smaller toes.

Bulimia nervosa is a serious eating disorder and mental health condition. People with bulimia can find themselves trapped in a cycle of eating a large amount of food (also called bingeing). They then use methods like vomiting, over exercising or using laxatives to get rid of the food.

Bronchitis is an infection of the main airways of the lungs (bronchi). It causes them to become irritated and inflamed.

Bronchiectasis is a long-term condition where the airways of the lungs become abnormally widened. It leads to a build-up of mucus (phlegm) that can increase risk of infection. It can affect anyone at any age, but symptoms don’t usually develop until middle age.

Breast cancer can be invasive or non-invasive (in-situ). When people talk about breast cancer, they usually mean invasive breast cancer. This is when cancer cells have spread outside the milk ducts or lobules in the breasts where they started, into surrounding breast tissue.

A primary brain tumour is a tumour that starts in the brain. The brain controls how we think, feel, learn and move. It also controls other important things in the body, such as breathing and heart rate. The brain is protected by the skull.

Brain stem death is when a person no longer has any brain stem function. When someone loses their brain stem function permanently, medical professionals will confirm they’re dead.

Bow legs mean that there is a gap between the knees when the ankles are pressed together. Knock knees are present when there is a gap between the ankle bones when the knees are pressed together.

Bowel polyps are small growths on the inner lining of the colon (large bowel) or rectum. They are common, affecting 15% to 20% of the UK population, and don’t usually cause symptoms.

Bowel incontinence is an inability to control bowel movements, resulting in involuntary soiling. It’s also sometimes known as faecal incontinence.

The bowel is part of the digestive system and is divided into the small bowel and large bowel. The large bowel is made up of the colon, rectum and anus. The term bowel cancer is normally used to talk about: colon cancer rectal cancer.

Children sometimes sit on their bottoms and move themselves around using their legs instead of crawling. This is known as bottom shuffling.

Primary bone cancer is a cancer that starts in a bone. It is sometimes called a bone sarcoma. This is different from secondary bone cancer. Secondary bone cancer is cancer that has spread to the bone, from a cancer elsewhere in the body. This is also called bone metastasis. Your doctor will tell you whether the bone cancer you have is primary or secondary.

The bladder is an organ that collects and stores pee (urine). It has 4 layers, including a layer of muscle. In the UK, over 10,000 people are diagnosed with bladder cancer each year. The actual number is likely to be higher than this because of the way this information is collected.

Bipolar disorder is a condition that affects your mood. You’re likely to have periods where your mood switches between: mania – feeling very high and overactive (less severe mania is known as hypomania) depression – feeling very low and lethargic.

Binge eating disorder (BED) is a serious eating disorder. Someone with BED will regularly eat very large quantities of food over a short period of time without feeling like they’re in control of what they’re eating. This eating behaviour causes feelings of distress and guilt and being overwhelmed.

Bile duct cancer (cholangiocarcinoma) is a rare cancer that starts in the lining of the bile duct.

Benign prostate enlargement (BPE), also known as benign prostatic hyperplasia (BPH), is a condition that affects older men and anyone with a prostate.

Becker muscular dystrophy is a muscle wasting condition which usually only affects males. It affects similar areas of the body to Duchenne MD but the symptoms tend to be less severe.

Bacterial vaginosis is not a sexually transmitted infection. It’s an imbalance of the usual bacteria found in the vagina.

Angioedema is the swelling of the deeper layers of the skin, caused by a build-up of fluid.

Angina is chest pain which occurs when the blood supply to the heart becomes restricted because of narrowing or blockages in the blood vessels around the heart.

Anaphylaxis is a severe, potentially life-threatening allergic reaction that can develop rapidly. It is also known as anaphylactic shock.

Anal cancer is a cancer that starts in the anus. The anus is the opening at the end of the large bowel, which is part of the digestive system. It is where you pass poo (stools) out of the body. It is part of the large bowel which includes the colon and rectum.

Dementia is an umbrella term for a range of conditions that affect different brain functions, including memory. Alzheimer’s disease is the most common type of dementia.

Allergic rhinitis is inflammation (redness and swelling) of the inside of the nose. It’s caused by an allergen, such as pollen, dust, mould, or flakes of skin from certain animals.

Alcohol-related liver disease (ARLD) refers to liver damage caused by excess alcohol intake. There are several stages of severity and a range of associated symptoms.

Adenomyosis is a condition that causes the lining of the womb (the endometrium) to bury into the muscular wall of the womb.

Addison’s disease (also known as primary adrenal insufficiency or hypoadrenalism) is a rare disorder of the adrenal glands.

Acute respiratory infections (ARIs) affect parts of the body that are used for breathing, such as the sinuses, throat or lungs and airways.

Acute pancreatitis is a serious condition where the pancreas becomes inflamed over a short period of time. The pancreas is a small organ located behind the stomach and below the ribcage.

Acute myeloid leukaemia (also called AML or AML leukemia) is a cancer of the blood cells. If you have leukaemia your body makes some abnormal blood cells. These leukaemia cells behave differently from healthy blood cells. Acute means that it develops quickly and needs to be treated straight away.

Acute lymphoblastic leukaemia (also called ALL or ALL leukemia) is a cancer of the blood cells. It is sometimes called acute lymphocytic leukaemia. If you have leukaemia your body makes some abnormal blood cells. These leukaemia cells behave differently from healthy blood cells.

Acute cholecystitis is swelling (inflammation) of the gallbladder. It is a potentially serious condition that usually needs to be treated in hospital.

Acne is a common skin condition that often develops on the face, back or chest. It causes spots, oily skin, deeper cysts and sometimes skin that’s hot or painful to touch.

Achilles tendinopathy, sometimes known as tendinitis, is a condition that can cause pain, stiffness and swelling of the Achilles tendon. This is a tendon connecting your calf muscle to your heel.

An abdominal aortic aneurysm (AAA) is a swelling (aneurysm) of the aorta – the main blood vessel that leads away from the heart, down through the abdomen to the rest of the body.