Coma

Overview

A coma is a state of deep unconsciousness. Someone in a coma cannot be woken up — not by calling their name, shaking them, or even by pain. Their eyes stay closed, and they do not speak, move on purpose, or respond to what is happening around them. A coma is not a disease on its own. It is a sign that something serious is affecting the brain, such as a severe injury, a stroke, an infection, or a very low blood sugar level. It is always a medical emergency, and the person needs care in hospital right away. Some people wake up within days, some take weeks or longer, and some move into a lighter state of awareness (such as being awake but not fully aware) as they recover. Coma is different from sleep, and a person in a coma cannot be 'woken' like a sleeper.

Coma is uncommon. It is mostly seen in hospital emergency departments and intensive care units, usually after a severe injury or illness. Because it is a sign of another problem rather than a single condition, exact numbers are hard to give, but it is not something most people will ever see outside a hospital setting.

Coma can affect anyone at any age, from young children to older adults. It is more likely in people who have had a severe head injury, a stroke, a cardiac arrest (when the heart stops), a serious infection of the brain, a very high or very low blood sugar level, or a severe reaction to alcohol, drugs, or poisons. People who take blood-thinning medicines or who have long-term liver or kidney problems may also be at higher risk.

Symptoms

Common symptoms

• Eyes stay closed and do not open, even when the person is spoken to or touched
• No response to voice, touch, or painful stimulation
• No purposeful movement, speech, or facial expression
• No awareness of surroundings or of people in the room
• Breathing that may be slow, fast, noisy, or irregular
• Sometimes seizures, twitching, or unusual body postures
• Loss of bladder or bowel control
• The person may look 'asleep' but cannot be woken

Symptoms in children

• Unusual sleepiness that keeps getting worse, or being hard to wake
• Not responding to a parent's voice or touch
• A change in breathing pattern, or noisy breathing
• A seizure, or a body that goes stiff or floppy
• Vomiting repeatedly, especially after a fall or bump to the head
• In babies: poor feeding, unusual floppiness, or a high-pitched cry before becoming unresponsive

Symptoms in older adults

• Becoming confused or drowsy much faster than expected during an illness
• Unresponsiveness after a fall — even a fall with no visible injury
• Sudden collapse linked to a stroke, infection, or a change in medicines
• Very low blood sugar in people with diabetes, which can cause drowsiness or unresponsiveness
• Dehydration or a severe infection that causes sudden confusion and then reduced consciousness

Causes

Main causes

• Severe head injury, such as from a road crash, fall, or assault
• Stroke, or bleeding inside the brain
• Lack of oxygen to the brain, for example after the heart stops, drowning, or choking
• Long or repeated seizures
• Infections of the brain and its coverings, such as meningitis or encephalitis
• Very low or very high blood sugar, especially in people with diabetes
• Serious problems with the liver, kidneys, or salt and water balance in the body
• Alcohol, drugs, or poisons, including accidental overdose
• Very low body temperature, or heat stroke
• Brain tumours or other growths pressing on the brain
• Severe complications of pregnancy, such as eclampsia (a serious condition with seizures and high blood pressure)
• In children: severe infections, accidents, swallowed poisons, or complications around birth

Risk factors

• A previous serious head injury or brain condition
• Epilepsy or a history of seizures
• Diabetes, especially with frequent high or low blood sugar
• Heavy or long-term alcohol use, or use of recreational drugs
• Taking blood-thinning medicines, which raise the risk of bleeding in the brain after a knock
• Older age, especially with frailty or many medicines
• Long-term liver or kidney disease
• Not wearing a helmet or seatbelt, or working in a high-risk job
• Being alone or far from help after an accident

When to see a doctor

See a doctor urgently if:

• Someone who is very drowsy, hard to wake, or becoming more confused
• Any loss of consciousness, even for a few seconds
• A head injury with vomiting, a severe headache, or memory gaps
• A seizure, or a first-time seizure
• A person with diabetes who becomes confused or sleepy and does not improve after their usual low-sugar treatment
• Sudden weakness, drooping face, or slurred speech — call emergency services, do not wait

Book a routine appointment if:

• After recovery from a coma or a serious brain illness, to plan follow-up and rehabilitation
• To review medicines that could cause drowsiness or confusion
• To manage long-term conditions such as diabetes, high blood pressure, epilepsy, or liver and kidney disease
• To talk about advance care planning and what matters to you and your family
• For family members who feel anxious, low, or overwhelmed after a loved one's illness

Diagnosis

A coma is recognised from the outside first: the person cannot be woken and does not respond. Doctors then work quickly to find the cause. They check breathing, pulse, and blood pressure, and use a simple scoring system called the Glasgow Coma Scale, which grades how the person opens their eyes, speaks, and moves. Family members are often asked what happened and what medicines the person takes, because this information can be vital. Treatment and testing often happen at the same time in an emergency department or intensive care unit.

Tests that may be done

• Physical and neurological examination, including the Glasgow Coma Scale
• Blood tests to check sugar, salts, oxygen, liver and kidney function, and possible infection
• CT scan or MRI scan of the brain to look for bleeding, swelling, stroke, or injury
• Electroencephalogram (EEG) — a painless recording of the brain's electrical activity, useful for spotting hidden seizures
• Lumbar puncture (spinal tap) if an infection of the brain is suspected
• Tests for drugs, alcohol, or poisons
• Chest X-ray or other imaging if breathing or the heart is affected

What to expect at your appointment

In the first hours, the focus is on keeping the person safe and stable: protecting the airway, helping breathing, and supporting blood pressure. You may be asked many questions at a stressful time, and you may not be able to stay in the room during scans. Staff will explain what is happening as often as they can. Doctors may not be able to give a clear answer about the cause or the outlook straight away — it often takes hours or days of tests and watching to understand more. It can help to have one family member take notes and share updates with others.

Treatment

There is no single treatment for coma itself. Care has two parts: treating the cause, and supporting the body while the brain recovers. Examples include oxygen and breathing support, fluids and nutrition through a drip, treating infection, controlling seizures, or correcting blood sugar. The person is watched closely, often in an intensive care unit, and care is adjusted as tests come back and as they respond.

Self-care at home

• If you are with someone who is unresponsive: check for a response, check breathing, call your local emergency number, and start CPR if you are trained and they are not breathing normally
• Never leave an unresponsive person alone, and do not give them food or drink
• If you are a family member: keep a notebook of questions, dates, and updates — it helps you track a fast-moving situation
• Take breaks, eat, and sleep where you can; ask a relative or friend to help coordinate visitors and calls
• Ask the care team who your main contact is and when updates are likely
• Follow all discharge and follow-up instructions carefully once the person leaves hospital
• Make the home safe before a person returns — remove trip hazards and arrange help with daily tasks

Medical treatments

Treatment is aimed at the cause and at protecting the brain. This can include oxygen or a breathing machine, fluids and nutrition given through a vein or a feeding tube, medicines to treat infection, to control seizures, or to correct blood sugar and salt levels, and close monitoring of the heart and brain. Nurses provide regular care to protect the skin, mouth, eyes, and joints, and physiotherapists help keep the body moving gently. As the person improves, care shifts towards rehabilitation — speech, movement, and thinking therapy — and towards supporting the family.

When is surgery considered?

Surgery may be needed if the cause is something that can be repaired, such as bleeding or pressure inside the brain, a brain tumour, or a build-up of fluid. The medical team will explain the risks and benefits, and decisions are made together with the family where possible. Many causes of coma do not need surgery at all.

Living with this condition

Coming out of a coma is usually gradual, not instant. A person may move through stages — waking briefly, being confused or agitated, sleeping a lot, and slowly becoming more aware. This can be frightening to watch, and it is normal for progress to be uneven. In the early weeks, life often centres on hospital appointments, therapy sessions, and helping with meals, movement, and personal care. Later, the focus shifts to rebuilding routines at home, with rehabilitation continuing for months. It helps to keep a simple daily record of sleep, mood, and any changes, and to share it with the care team.

Lifestyle tips

• Keep a calm, familiar routine with regular sleep and wake times
• Follow the rehabilitation plan — short, regular practice is better than long, tiring sessions
• Keep the home safe: good lighting, clear pathways, grab rails, and no loose rugs
• Limit alcohol and avoid recreational drugs, which can affect the brain and recovery
• Build in rest breaks — fatigue is very common after a brain injury or long illness
• Stay connected with friends and family, even in small ways such as short visits or calls
• Ask your doctor before driving or returning to work or sport

Diet and exercise

Good nutrition supports brain recovery. A dietitian can advise on foods and portion sizes, and on any texture changes if swallowing has been affected. Swallowing problems must be checked by a professional before normal food and drink are restarted, because of the risk of choking or chest infection. Exercise should start gently and be guided by the rehabilitation team — often starting with sitting balance, stretches, and short walks, then building up slowly. Children and older adults need plans tailored to them.

Mental health and emotional wellbeing

A coma affects the whole family, not just the patient. Partners, parents, and children often describe shock, guilt, fear, exhaustion, and a sense of grief for the person they knew — even when recovery goes well. Survivors may feel frustrated, anxious, low, or different from before, and may struggle with memory or mood. These feelings are common and treatable. If you or a loved one feels overwhelmed, or has thoughts of self-harm, contact your local emergency number or a crisis support service right away, and tell your doctor or care team — help is available.

Prevention

Many, though not all, causes of coma can be prevented or made less likely. Wearing a seatbelt and a helmet, driving safely, and making homes safer for older people all reduce the risk of serious head injury. Good control of diabetes, blood pressure, and epilepsy lowers the risk of coma from those conditions. Avoiding heavy alcohol use and taking medicines exactly as prescribed — and never mixing them with alcohol or other people's medicines — also helps. If someone is unresponsive, quick action with emergency services and CPR saves lives and can reduce lasting brain damage.

Vaccines

Routine vaccinations, including those recommended against infections that can affect the brain such as meningitis, help protect against some causes of coma. Ask your doctor or pharmacist which vaccines are recommended for you or your child.

Screening programmes

Regular checks of blood pressure, blood sugar, and heart health can catch problems early, before they become serious. If you have diabetes, epilepsy, or a condition that affects the liver or kidneys, keeping up with your reviews and follow-up appointments is an important way to lower your risk.

Complications

If left untreated

• Lasting brain damage, which can affect movement, speech, memory, and thinking
• Chest infections such as pneumonia, especially if swallowing is affected
• Pressure sores and skin damage from lying still for a long time
• Blood clots in the legs or lungs
• Muscle tightness and joint stiffness from not moving
• Problems with swallowing and nutrition
• Infections of the bladder or bloodstream
• In the most serious cases, death

Long-term outlook

Coma is serious, and every case is different. Many people do wake up and make meaningful progress, and some recover fully or nearly fully. Others recover with lasting difficulties, and some continue in a lower state of awareness for a long time. The chance of recovery depends on the cause, how quickly help was given, how long the coma lasts, the person's age, and their health before. Doctors are often cautious about predictions early on, because the brain can recover slowly and in unexpected ways. Rehabilitation, family support, and good general care all make a difference, and the care team can give you honest, personal guidance as things become clearer.

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