Symptoms A–Z
Symptoms: causes and when to worry
Browse common symptoms to understand what can cause them and the warning signs that mean you should get urgent help — each cause links to a full, dose-free condition guide.
Education and reference only. A symptom can have many causes. These pages help you understand them and recognise warning signs — they are not a diagnosis or a substitute for medical advice.
Heart, chest & breathing
Chest Barking cough in a child A harsh, barking cough in a child, often worse at night and sometimes with a rasping noise when breathing in, which is usually due… Chest Breathlessness when lying down Becoming short of breath when lying flat, and needing to prop up on pillows or sit to breathe comfortably — often a sign of heart … Chest Chest pain Discomfort, pressure, tightness or sharp pain anywhere in the chest that can come from the heart, the food pipe and stomach, the l… Chest Cough A reflex to clear the airways that is usually caused by a viral infection and settles within a few weeks, but which when persisten… Chest Coughing up blood Coughing up blood or blood-streaked phlegm from the lungs or airways — which always needs prompt medical assessment, and which, wh… Chest Heartburn Heartburn is a burning feeling in the chest caused by stomach acid rising into the gullet, and while usually harmless, certain sym… Chest Palpitations An unusual awareness of your own heartbeat — feeling it race, pound, flutter or skip — which is most often harmless and triggered … Chest Shortness of breath A feeling of not being able to get enough air, breathing faster or harder than normal, or struggling for breath — which ranges fro… Respiratory Wheezing A high-pitched whistling sound when breathing, usually as air moves through narrowed airways.…
Head, brain & nerves
Head Balance problems and unsteadiness A feeling of being unsteady on your feet, swaying or about to fall — most often from inner-ear conditions affecting the body's bal… Head Difficulty concentrating / brain fog A frustrating sense of being mentally cloudy, forgetful or unable to focus, most often caused by poor sleep, stress, low mood or h… Head Dizziness A broad term covering a spinning sensation (vertigo), feeling faint or lightheaded, or feeling unsteady on your feet — most often … Head Dizziness when standing up Lightheadedness, wooziness or near-fainting that comes on when you stand up, caused by a brief drop in blood pressure as you rise … Head Facial swelling Swelling of part or all of the face — which can come from an allergic reaction, infection or sinus problem, and which, when it inv… Head Headache Pain anywhere in the head — from a tight band of tension to a throbbing migraine or sinus pressure — which is usually harmless and… Head Jaw pain Pain in the jaw — usually from the jaw joint, teeth or muscles, but occasionally a referred warning of a heart attack or, in older… Neurology Memory problems Memory problems mean finding it harder to remember things or think clearly, which can have many causes, not all of them serious.… Nerves Numbness and tingling Numbness and tingling happen when a nerve is irritated, compressed or not working properly, and while often harmless, sudden sympt… Head Poor coordination and clumsiness Difficulty controlling movement smoothly — dropping things, stumbling, or fumbling with everyday tasks — which can come from many … Head Seizures or fits A sudden burst of abnormal electrical activity in the brain that can cause shaking, stiffening, collapse or a brief loss of awaren… Head Slurred speech Speech that becomes slurred, slow or hard to understand — and when it starts suddenly, one of the clearest warning signs of a stro… Head Travel sickness The nausea, dizziness, cold sweats and queasiness that some people feel when travelling by car, boat, plane or fairground ride, ca… Neurology Tremor A tremor is a rhythmic shaking or trembling, most often of the hands, which can have many causes ranging from harmless to ones tha…
Mental health & mood
Mind Binge eating and loss of control with food Recurring episodes of eating a large amount of food with a sense of being unable to stop, often followed by distress, guilt or sha… Mental health Low mood Low mood means feeling sad, flat or down for a period of time, which can be a normal reaction or part of depression when it lasts.… Mind Mood swings Marked ups and downs in mood that can be a normal response to stress, sleep loss or hormonal change, but which sometimes reflect a… Mind Seeing or hearing things that are not there Seeing, hearing, feeling or smelling things that are not really there, which can have many causes ranging from severe tiredness or… Mind Sudden confusion or delirium A rapid change in thinking, awareness or behaviour that develops over hours or days, which is a medical emergency because it can b… Mind Unwanted intrusive thoughts Unwanted, distressing thoughts, images or urges that pop into the mind against your wishes, which are extremely common and usually…
Eyes & vision
Eyes Blurred vision Vision that is not as sharp or clear as usual, in one or both eyes, from a range of eye and general causes.… Eyes Double vision Seeing two images of a single object — a symptom that can come from the eye muscles, the nerves controlling them or the brain, and… Eyes Drooping eyelid An upper eyelid that hangs lower than usual, on one or both sides, which can develop slowly with age or muscle conditions, but whi… Eyes Eye pain Pain in or around the eye — often from a surface irritation, infection or dryness, but sometimes a sign of raised pressure inside … Eyes Floaters and flashing lights Small specks, threads or cobwebs that drift across your vision, sometimes with brief flashes of light — usually a harmless age-rel… Eyes Itchy eyes An itchy, watering or gritty sensation in one or both eyes that is most often due to allergy, infection, dryness or eyelid irritat… Eyes Red eye Redness of the white of one or both eyes, often from irritation or a minor infection.… Eyes Sensitivity to light Discomfort or pain in the eyes when exposed to light — most often part of a migraine or an eye-surface problem, but, when it appea… Eyes Sticky or discharging eye A sticky, crusty or running discharge from the eye — which can be watery, mucky or pus-like — usually caused by conjunctivitis, a … Eyes Swollen eyelid Puffiness or swelling of one or both eyelids — usually caused by a stye, blepharitis, an allergic reaction or a minor infection — … Eyes Watery eyes Eyes that overflow with tears or stream more than usual, most often from irritation, allergy, dryness or a blocked tear duct — usu…
Ear, nose & throat
Nose Blocked or stuffy nose A stuffy, congested or blocked nose where the lining is swollen and the airways feel obstructed — usually caused by a cold, an all… Ear Discharge from the ear Fluid running from the ear — which may be wax, watery, pus-like or bloodstained — most often caused by an infection of the ear can… Ear Ear pain Ear pain is common, especially in children, and is most often caused by an ear infection or referred pain from the throat, usually… Throat Feeling of a lump in the throat A persistent sensation of something stuck in the throat when nothing is actually there — usually a harmless feeling called globus … Nose Frequent sneezing Repeated, sudden bursts of sneezing as the nose tries to clear an irritant — most often from an allergy such as hay fever, a cold … Throat Hoarse voice A rough, raspy, weak or croaky change in the voice from irritation, swelling or strain of the vocal cords — usually short-lived af… Ear Itchy ears An irritating itch in or around the ears — most often caused by dry or eczema-prone skin, a build-up of debris, or a mild infectio… Nose Loss of smell A reduced or absent sense of smell — often dulling the sense of taste as well — which is most commonly caused by a blocked or infl… Nose Nosebleeds A nosebleed is bleeding from inside the nose, usually from small, delicate blood vessels near the front of the nostril.… Throat Sore throat Pain, scratchiness or rawness at the back of the throat that is usually caused by a passing viral infection but can also come from… Ear Tinnitus Tinnitus is hearing sound — such as ringing, buzzing or humming — that does not come from an outside source.…
Mouth, teeth & jaw
Mouth Bleeding gums Gums that bleed when you brush, floss or eat — usually a sign of gum inflammation from plaque build-up, but occasionally a clue to… Mouth Burning or sore mouth A burning, scalded or sore sensation in the mouth, tongue or lips — which can come from thrush, nutritional deficiencies, dryness … Mouth Dry mouth A persistent feeling that the mouth is dry and short of saliva — often a side effect of medicines, dehydration or breathing throug… Mouth Loss of taste A reduced or altered sense of taste, where food tastes bland, odd or of nothing at all — usually tied to a blocked or inflamed nos… Mouth Mouth ulcers Painful sores on the lining of the mouth, lips or tongue that are usually harmless and heal on their own within a couple of weeks,… Mouth Persistent bad breath An unpleasant smell from the mouth that does not clear with brushing — most often caused by oral hygiene problems, gum disease or … Mouth Sore, cracked lips and mouth corners Dry, sore, cracked or split lips, often with painful cracks at the corners of the mouth — usually from weather, dehydration, lip-l… Mouth Swollen tongue or lips Swelling of the tongue, lips or mouth that can be a harmless reaction or a sign of an allergic-type reaction, an infection or a de… Mouth Toothache Pain in or around a tooth — aching, throbbing or sharp — most often caused by decay, gum problems or a dental infection, but occas…
Skin, hair & nails
Skin Blisters on the skin Raised, fluid-filled bumps on the skin that can follow friction or burns, but also arise from skin conditions and infections — and… Nails Brittle or changing nails Nails that split, peel, ridge, crumble or change colour and shape — often simply from age, water exposure or minor damage, but som… Skin Bruising easily Bruises that appear with little or no injury, or seem larger or more frequent than expected — often harmless and related to ageing… Skin Dry, flaky skin Skin that feels rough, tight, flaky or scaly because it is short of moisture — usually down to weather, washing or a tendency to e… Face Facial redness and flushing Persistent or recurring redness, warmth or flushing across the cheeks, nose, chin or forehead that most often comes from common sk… Skin Hair loss Thinning or shedding of hair on the scalp or body that is most often a natural, gradual pattern of balding but can also follow str… Skin Itching Itching, known medically as pruritus, is most often caused by dry or irritated skin conditions, but persistent or widespread itchi… Scalp Itchy scalp An itchy, sometimes flaky or sore scalp — most often from common, treatable conditions such as head lice, dandruff-type dermatitis… Skin New or changing mole A mole or pigmented spot that is new, growing or changing in size, shape or colour, or that itches, bleeds or crusts — most are ha… Skin Pale skin Skin that looks paler than usual, sometimes with pale lips, gums or inner eyelids, which can simply reflect skin tone or cold, but… Skin Rash A change in the colour, texture or appearance of the skin — itchy or not, raised or flat, spreading or localised — usually from a … Scalp Scalp tenderness Soreness, sensitivity or pain of the scalp, often noticed when brushing the hair or touching the head — usually from muscle tensio… Skin Spreading circular rash A round or ring-shaped patch on the skin that spreads outwards, which most often comes from a fungal infection or eczema, but can …
Bones, joints & muscles
Ankle Ankle pain Pain, stiffness or swelling in or around the ankle joint that most often comes from a sprain, overuse or wear of the joint, but wh… Back Back pain Back pain is very common, usually comes from the muscles, joints or discs of the spine, and most often improves on its own within … Hands Finger clubbing A gradual change in the fingertips and nails, where the nail bed softens, the nail curves more and the fingertip broadens — usuall… Foot Foot pain Pain in any part of the foot — heel, arch, toes or the ball of the foot — most often from strained tissues, arthritis or gout, but… Hands Hand and finger pain Pain, aching or stiffness in the hands, fingers or thumb — most often from arthritis, a trapped nerve at the wrist, or circulation… Foot Heel pain Pain felt under or behind the heel — often sharpest on the first steps in the morning — that usually comes from strain of the tiss… Hip Hip pain Pain felt in the hip joint, groin, outer thigh or buttock — most often from wear-and-tear arthritis, inflamed tendons or the bursa… Joints Joint pain Pain, stiffness or swelling in one or more joints, ranging from everyday wear-and-tear arthritis to inflammatory and crystal arthr… Joints Knee pain Knee pain is discomfort in or around the knee joint, often from wear, injury or inflammation, and is very common at all ages.… Legs Leg pain Aching, cramping or sharp pain in one or both legs, from a range of muscle, joint, nerve or blood-vessel causes.… Legs Leg ulcers and slow-healing wounds Open sores on the lower leg or foot, or wounds that are slow to heal, usually caused by poor circulation, raised pressure in the l… Back Lower back pain Pain across the lower part of the back that is extremely common and usually due to muscle or joint strain that settles within a fe… Legs Muscle cramps Sudden, painful, involuntary tightening of a muscle — usually a harmless, short-lived spasm in the calf or foot, but one that must… Neck Neck pain Neck pain is discomfort or stiffness in the neck, usually from muscle or joint strain, and is common and most often short-lived.… Legs Restless legs An uncomfortable, often indescribable urge to move the legs — usually worse in the evening and at rest and relieved by movement — … Joints Shoulder pain Shoulder pain is discomfort in or around the shoulder joint, often from the soft tissues, and can limit reaching, lifting and slee… Legs Swollen ankles Swollen ankles and legs are usually caused by fluid building up in the tissues, which can range from a harmless effect of standing…
Stomach & digestion
Abdomen Abdominal pain Pain anywhere between the chest and the groin — cramping, burning, gnawing or sharp — which usually comes from the digestive syste… Digestive Bloating A feeling of fullness, tightness or swelling in the tummy, often with trapped wind.… Bottom Blood in your stool / rectal bleeding Blood seen on the toilet paper, in the pan or mixed through the stool — most often from piles or a small tear, but always a sympto… Digestive Constipation Passing stools less often than usual, or finding them hard, dry and difficult to push out — a very common problem usually linked t… Digestive Diarrhoea Passing looser or more frequent stools than normal, usually settling within a few days.… Digestive Difficulty swallowing Trouble getting food or drink to go down, or a sense that it sticks or is painful on the way.… Stomach Feeling full quickly Feeling full after eating only a small amount, or losing your appetite earlier than usual — often from indigestion, reflux or a se… Bottom Itchy bottom An irritating itch around the back passage — often worse at night — that is usually caused by skin irritation, piles, threadworms … Stomach Pulsating lump in the abdomen A throbbing or pulsating feeling, or a visible lump, in the centre of the tummy that beats in time with the heart — which can be a… Stomach Swollen or bloated abdomen A tummy that feels full, tight, distended or visibly larger than usual — most often from trapped wind, constipation or the menstru… Stomach Vomiting Bringing up the contents of the stomach — usually a short-lived response to a tummy bug, migraine or something that has upset the … Stomach Wind and bloating with flatulence Frequent burping, a bloated, full tummy and passing more wind than usual, almost always from normal digestion, swallowed air or a …
Bladder & kidneys
Urine Blood in urine Blood in the urine should always be checked by a doctor, as while many causes are treatable infections or stones, it can occasiona… Urinary Difficulty passing urine Trouble starting to pass urine, a weak or stop-start stream, straining or a feeling the bladder has not emptied, most often from a… Urine Frequent urination Needing to pass urine more often than usual, by day or night, which can be due to a bladder infection, an enlarged prostate, an ov… Urinary Pain when passing urine Burning, stinging or discomfort when passing urine — most often a urine infection, but sometimes a sign of a kidney infection, a s…
Sexual & reproductive health
Breast Breast lump A new lump, thickening or change in the breast — which is most often a benign change such as a cyst, hormonal lumpiness or infecti… Reproductive health Erectile problems Erectile problems mean difficulty getting or keeping an erection firm enough for sex, which is common and often treatable.… Groin Groin lump A lump in the groin — most often a swollen gland, a hernia, a cyst or an inflamed hair follicle or skin gland — which is frequentl… Periods Irregular periods Periods that come unpredictably, too often, too rarely, or with cycles that vary in length, which can be a normal variation but ca… Pelvic Pain during sex Pain felt during or after sex, either at the entrance or deeper inside, which is common, often very treatable, and can have physic… Pelvis Pelvic pain Pain low in the tummy or pelvis that often comes from the reproductive organs, bladder or bowel and is frequently linked to period… Testicles Testicular pain or lump Pain, swelling or a lump in a testicle, which can come from infection or minor causes but which, when sudden and severe — especial… Reproductive health Vaginal discharge Vaginal discharge is normal fluid from the vagina, but a change in its colour, smell, amount or texture can sometimes signal an in…
Sleep
Sleep Excessive daytime sleepiness A persistent struggle to stay awake during the day — nodding off, fighting heavy eyelids or feeling unrefreshed by sleep — which u… Sleep Snoring A rattling, snorting or whistling noise made when breathing during sleep as air passes a partly narrowed throat — usually harmless…
General & whole-body
General Blue lips or skin A bluish or grey tinge to the lips, tongue, face or skin that means the body is not getting enough oxygen — a warning sign that sh… General Chills and shivering A feeling of being cold with shivering or shaking, usually as the body raises its temperature to fight an infection — most often a… Hands & feet Cold or discoloured hands and feet Hands or feet that feel persistently cold or change colour — turning white, blue or red — usually because small blood vessels narr… General Cold sweats Breaking out in a clammy, cold sweat that is not caused by heat or exertion — often a normal response to fear, pain or low blood s… General Excessive hunger A persistent or unusually strong urge to eat that is out of keeping with your normal appetite — which can be a harmless response t… General Excessive sweating Excessive sweating means sweating more than the body needs to cool itself, which can affect the whole body or just certain areas.… General Excessive thirst A persistent, abnormal thirst that is not satisfied by drinking — which can simply follow heat, exercise or salty food, but when c… General Fatigue A persistent lack of energy or overwhelming tiredness that is not relieved by rest and interferes with normal life — usually expla… General Feeling cold all the time Feeling cold when others are comfortable, or being unusually sensitive to cold, which is often simply down to body type or environ… General Feeling faint Feeling light-headed and as though you might pass out, or briefly losing consciousness.… General Fever A fever is a rise in body temperature, usually above 38°C, and is most often a sign that the body is fighting an infection.… General Frequent infections Catching infections more often than expected, or finding they are more severe, slow to clear or keep coming back, which can simply… General Hot flushes Sudden waves of heat, flushing and sweating, often spreading over the face, neck and chest, that are most commonly part of the men… General Muscle weakness A genuine loss of strength in one or more muscles — different from simply feeling tired — which when it comes on suddenly or on on… General Night sweats Sweating heavily during sleep, often enough to soak your nightclothes or bedding.… General Swollen glands Tender, enlarged lymph nodes, often in the neck, usually reacting to a nearby infection.… General Unintentional weight loss Losing weight without trying should always be assessed by a doctor, as it can be caused by a range of conditions including thyroid… General Weight gain Weight gain is an increase in body weight, which is usually due to diet and activity but can occasionally reflect a hormonal or ot… General Yellow skin or eyes A yellowing of the whites of the eyes and the skin caused by a build-up of bilirubin, a pigment normally cleared by the liver — wh…
Answers
About the symptoms A–Z
What do the symptom pages tell me?
Each symptom page explains the common conditions that can cause that symptom, what can help, and — most importantly — the red-flag warning signs that mean you should get urgent or emergency help. Each cause links to a full guide to that condition.
Can I use these to diagnose myself?
No. A symptom can have many causes, and these pages are education and reference only — not a diagnosis. They help you understand what might be going on and when to seek help, but a clinician should assess your own symptoms.
When should I call 999?
Each symptom page lists its specific red flags. In general, call 999 for sudden severe chest pain, difficulty breathing, signs of a stroke (face drooping, arm weakness, slurred speech), a fit, a rash that does not fade under a glass with feeling unwell, or if someone is very unwell or unresponsive.
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