Unconsciousness (Loss of Consciousness)

Unconsciousness means a person is unable to respond to voice, touch or their surroundings. It may be brief, as in a simple faint, or long-lasting, as in a coma. Any unexplained loss of consciousness should be treated as a medical emergency until a doctor has found the cause.

Symptoms

• Not responding to voice, touch or pain
• Sudden collapse or fall
• Confusion, drowsiness or difficulty waking up
• Abnormal, noisy or very slow breathing
• Jerking movements of the body, which may suggest a seizure
• Loss of bladder control
• Pale, sweaty skin or dizziness just before a faint

Causes

• Fainting (syncope) due to a sudden drop in blood pressure or a heart rhythm problem
• Head injury, with bleeding or swelling of the brain
• Stroke or bleeding inside the brain, for example from high blood pressure or a burst blood vessel (aneurysm)
• Seizures
• Very low or very high blood sugar
• Brain infections such as meningitis or encephalitis
• Brain tumour or build-up of fluid in the brain (hydrocephalus)
• Poisoning, alcohol or drug overdose, and liver or kidney failure
• Lack of oxygen, as in choking or drowning, and heat stroke

Diagnosis

Doctors first check the airway, breathing, pulse, blood pressure and blood sugar. A neurological examination assesses the level of consciousness. A CT scan of the brain is usually done urgently to look for bleeding, injury or swelling, and an MRI may be needed later. Blood tests, an ECG and, in some cases, an EEG or a test of the spinal fluid help find the cause.

Treatment

Treatment depends entirely on the cause. The first priority in hospital is to protect the airway, support breathing and blood pressure, and correct problems such as low sugar. A simple faint often needs only reassurance and advice, while heart rhythm problems are treated by a heart specialist. Seizures, infections and poisoning are treated with appropriate medicines.

When scans show a surgical cause, such as a blood clot after a head injury, bleeding in the brain, raised pressure from fluid build-up, or a brain tumour, urgent neurosurgery may be needed to relieve pressure on the brain. Some patients need care in an intensive care unit, followed by rehabilitation.

When to Seek Urgent Care

• The person does not wake up within a minute or two
• Loss of consciousness after a head injury, even if the person seems to recover
• Unconsciousness with a seizure, weakness of one side, severe headache or vomiting
• Breathing difficulty, no breathing or no pulse
• Fainting during exercise, or with chest pain or a racing heartbeat
• Unconsciousness in a person with diabetes, heart disease, pregnancy or on blood-thinning medicines

In any of these situations, call an ambulance or take the person to the nearest emergency immediately.

While waiting for help: check breathing. If the person is breathing, turn them on to their side to keep the airway clear and prevent choking on vomit. If there may be a neck or spine injury, keep the head and neck still. Do not give food, water or medicines by mouth, and do not leave the person alone. If they are not breathing, start CPR if you are trained. Note the time it happened.

After any episode of unexplained loss of consciousness, consult Dr. Prashant Sharma for a thorough evaluation of brain-related causes.

Related Conditions

• Vertigo
• Head Injury
• Blood Clot in the Brain
• Brain Haemorrhage
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