Coma

Diagnosis

To diagnose coma, healthcare professionals rely on physical clues and information provided by families and friends. Helpful information includes:

• Events leading up to the coma, such as vomiting or headaches.
• Details about how the person lost consciousness, including whether it occurred quickly or over time.
• Symptoms before losing consciousness.
• Medical history, including other conditions the person may have had in the past. This includes whether the person has had a stroke or ministroke, also called a transient ischemic attack.
• Recent changes in the person's health or behavior.
• Medicine and drug use, including prescription medicines, medicines taken without a prescription, and legal and illegal drugs.

Physical exam

The exam is likely to include:

• Checking the person's movements and reflexes, response to painful stimuli, and pupil size.
• Observing breathing patterns to help diagnose the cause of the coma.
• Checking the skin for signs of bruises due to trauma.
• Speaking loudly or pressing on the angle of the jaw or nail bed while watching for signs of arousal, such as vocal noises, eyes opening or movement.
• Testing reflexive eye movements to help figure out the cause of the coma and the location of brain damage.
• Squirting cold or warm water into the affected person's ear canals and watching eye reactions.

Laboratory tests

Blood samples typically are taken to check for:

• Complete blood count.
• Electrolytes and sugar, also known as glucose.
• Thyroid, kidney and liver functions.
• Carbon monoxide poisoning.
• Drug or alcohol overdose.

A spinal tap, also known as a lumbar puncture, can check for signs of infections in the nervous system. During this test, a healthcare professional inserts a needle into the spinal canal and collects a small amount of fluid for analysis.

Brain scans

Imaging tests help pinpoint areas of brain injury. Tests might include:

• CT scan. This uses a series of X-rays to create a detailed image of the brain. A CT scan can show bleeding in the brain, tumors, strokes and other conditions. This test is often used to diagnose and find the cause of a coma.
• MRI. This uses powerful radio waves and a magnetic field to create a detailed view of the brain. An MRI scan can detect bleeding in the brain, brain tissue damaged by an ischemic stroke and other conditions. MRI scans are particularly useful for examining the brainstem and deep brain structures.
• Electroencephalogram (EEG). This measures the electrical activity inside the brain through small metal discs called electrodes attached to the scalp. This test can help find if seizures might be the cause of a coma.

Treatment

Coma requires emergency treatment. Healthcare professionals typically first check the airway and help support breathing and circulation. Treatment might include breathing help, medicines through a vein and other supportive care.

Treatment depends on the cause of the coma. A procedure or medicines to relieve pressure on the brain due to brain swelling might be needed. Emergency responders might give glucose or antibiotics through a vein in the arm. These may be given even before blood test results return in cases of very low blood sugar or an infection affecting the brain.

If the coma is the result of a medicine or drug overdose, healthcare professionals typically give medicines to treat the condition. If the coma is due to seizures, medicines can control seizures. Other treatments might focus on medicines or therapies to address an underlying disease, such as diabetes or liver disease.

Sometimes the cause of a coma can be completely reversed, and the person regains function. Recovery usually occurs gradually. A person with serious brain damage might have permanent disabilities or never regain consciousness.

Preparing for your appointment

Coma is an emergency medical condition. If you are with a person who develops symptoms of a coma, call 911 or emergency medical help right away.

When you arrive at the hospital, emergency room staff will need as much information as possible from family and friends about what happened to the person before the coma. You might be asked the following questions:

• Did the coma start suddenly, or did it happen more gradually?
• Were there problems with vision, dizziness or weakness beforehand?
• Does the person have a history of diabetes, seizures or strokes?
• Did the person talk about changes in health in the time leading up to the coma, such as a fever or worsening headache?
• Did you notice changes in the person's ability to function before the coma, such as falls or confusion?
• Did the person use prescription medicines, medicines you can buy without a prescription, or legal or illegal drugs?