How is the condition diagnosed?
When a person is unconscious and does not respond to painful stimulation, this is generally considered a medical emergency. Diagnosis begins with a history and physical exam. Information obtained from friends, family members, or witnesses may be life saving. For example, knowing that a person was recently using large amounts of heroin may allow quick treatment that can reverse the coma.
In many cases, further tests are needed to help figure out the cause of a coma. For example, blood tests can detect salt imbalances, low blood sugar, and other conditions. Urine tests may help detect drugs in someone's system or diagnose kidney disease. X-ray tests, such as a cranial CT scan of the brain, may detect a stroke, brain tumor, or bleeding into or around the brain. Other tests may be needed in certain cases.