Illnesses and symptoms, A to Z.

Each page explains the illness in plain words: the signs, the tests, when to go to hospital, and what to have ready for a consultation.

Acidity and gastritis Stomach acid burning where it shouldn't: up the food pipe, or on an irritated stomach lining.
Allergies: sneezing, runny nose, wheeze The body over-reacting to harmless dust or pollen: sneezing, runny nose, wheeze.
Anaemia Too little haemoglobin, the red protein that carries oxygen, so less reaches the body.
Asthma Airways that squeeze, swell and fill with mucus. The right inhalers keep them calm.
Black stools or vomiting blood Usually bleeding in the stomach or food pipe. Go to hospital now, even if you feel well.
Bloating and IBS A sensitive gut: pain, bloating and a changed bowel habit, with normal tests.
Blood in the stools Always worth checking, even a little. Black, tarry stools or heavy bleeding need hospital now.
Boils and skin infections A pocket of pus around a hair root. Spreading redness or fever needs a doctor.
Breathlessness From the lungs, the heart or the blood. Sudden or severe breathlessness: call 112.
Chest infections Germs filling the lungs’ tiny air sacs with pus. Fever, cough and breathlessness; some need hospital.
Chest pain Treat it as the heart until a test says otherwise. Lasting or at-rest chest pain: call 112.
Constipation Hard, dry stools, passed rarely or with straining. Usually eased by fibre, water and moving more.
COPD Airways narrowed and air sacs damaged, mostly by smoke. Inhalers and quitting smoking help.
Cough, cold and sore throat Germs, mostly viruses, on the lining of the nose, throat or airways. Most settle on their own.
Crohn's disease and ulcerative colitis (IBD) Long-lasting inflammation of the bowel: loose motions with blood, pain, weight loss. Needs long-term care.
Dengue A virus from a day-biting mosquito. The risky days often come as the fever falls.
Diabetes Too much sugar stays in the blood, because insulin is missing or not working well.
Fainting Usually a harmless common faint. A faint on effort, lying down or with no warning needs urgent checks.
Fatty liver Extra fat stored inside the liver's cells. Common, silent, and worth checking.
Fever The body turning its own thermostat up, most often to fight a virus.
Fever that keeps returning, or has no clear cause A fever that lasts for weeks or keeps returning. The cause can usually be found, step by step.
Fits (epilepsy) Fits from sudden bursts of electrical activity in the brain. Medicines control them in most people.
Gallbladder stones Stones in the gallbladder. Often silent; pain in the upper right tummy after meals needs a check.
Gout and high uric acid Uric acid crystals in a joint, often the big toe: sudden, hot, swollen pain. Keeping uric acid low prevents most attacks.
Headache and migraine Most are tension headaches or migraine. A sudden, severe one is an emergency.
Heart disease Narrowed heart arteries. Chest pain on effort is a warning; chest pain that does not settle needs 112.
Heart failure A heart pumping too weakly. Fluid backs up: breathlessness and swollen ankles.
Hepatitis B and C Viruses passed by blood that quietly scar the liver. Testable, treatable, preventable.
High BP Blood pushing too hard on the artery walls. Usually felt as nothing at all.
High cholesterol Too much of the fat called LDL in the blood, slowly lining the arteries. Felt as nothing.
Hives (urticaria) Raised, itchy welts that fade within a day. Swelling of the lips or throat is an emergency.
Infections that keep coming back The same infections again and again. Often one treatable reason, and high sugar tops the list.
Jaundice Yellow eyes and dark urine, from bilirubin building up. The cause needs finding.
Joint pain and arthritis Pain where two bones meet: from wear, inflammation, crystals or infection. The pattern tells which.
Kidney damage (chronic kidney disease) Slow loss of the kidneys' filters, often from sugar or BP. Silent until late.
Kidney stones Salts in the urine turning into a stone. One on the move brings sudden, severe pain from side to groin.
Loose motions (diarrhoea) Watery stools, usually from a germ. The danger is losing water, and ORS puts it back.
Losing weight without trying Losing weight when you are not trying. Usually a treatable cause, worth finding soon.
Low sugar (hypoglycaemia) Sugar below 70 on insulin or some tablets. Fast sugar if the person can swallow; if not, call 112.
Malaria A mosquito-borne parasite in the red cells: fever with chills. Needs a blood test the same day.
Many medicines, several illnesses at once Tablets from several doctors add up. One review spots doubles and clashes. Never stop one alone.
Numbness, tingling and nerve pain Damaged nerves, often from sugar or low B12. Tingling, burning or numb feet first.
Prediabetes Sugar above normal but not yet diabetes. The stage when it can often be turned back.
Protein or blood in the urine A leak in the kidneys' filters, or bleeding lower down. Always worth checking.
Raised liver tests (LFT) Liver cells spilling their enzymes into the blood. A clue worth following up.
Rashes and itching Red, itchy or scaly skin. Where it is and how it looks usually point to the cause.
Snoring and sleep apnoea A throat that narrows or closes in sleep. Loud snoring with pauses is worth checking.
Stress, low mood and poor sleep Worry, poor sleep and low mood feed each other. Common, treatable, and no sign of weakness.
Stroke: lowering the risk, and after one A blocked or burst artery in the brain. Face drooping, arm weak, speech slurred: call 112 at once.
Thyroid problems The gland in the neck that sets the body's speed, running too slow or too fast.
Tiredness and weakness Usually sleep, stress or mood; sometimes anaemia, thyroid or sugar. A few blood tests tell.
Typhoid A germ from unsafe water or food that crosses the gut into the blood. Needs the right antibiotic.
Urine infections Germs climbing into the bladder, causing burning urine. More serious if they reach a kidney.
Vitamin B12 deficiency Common in vegetarians and on metformin. Causes anaemia, tiredness and tingling feet.
Vitamin D deficiency Too little of the vitamin that lets the body take up calcium. Bones ache and thigh muscles tire.
Weight gain and obesity Extra body fat. The fat deep around the waist matters most for health.