Decreased consciousness is reduced alertness or awareness.
Stuporous; Mental status - decreased; Loss of alertness; Decreased consciousness; Alertness - decreased; Changes in consciousness; Obtundation; Coma; Unresponsiveness
Many conditions can cause decreased consciousness, including:
A decrease in consciousness almost always require a doctor's attention, except perhaps when due to alcohol intoxication, simple fainting, or a previously recognized seizure disorder.
See the article on seizures for tips on how to care for a person who is having a seizure.
Persons with epilepsy or other seizure disorder should carry a Medic-Alert bracelet or pendant describing their condition. Such individuals should avoid situations that have previously triggered a seizure.
See medical help if someone has unexplained, decreased consciousness. Call your local emergency number (such as 911) if normal consciousness does not return quickly.
Most often, a person with decreased consciousness will be evaluated in an emergency room setting.
The doctor will perform a physical examination. The exam will include a detailed look at the cardiovascular, respiratory, and nervous systems.
The health care team will ask questions about the person's medical history and symptoms, including
- Time pattern
- When did the decreased consciousness occur?
- How long did it last?
- Has it ever happened before? If so, how many times?
- Did the person behave the same way on previous episodes?
- Medical history
- Does the person have known epilepsy or seizure disorder?
- Does the person have diabetes?
- Has the person been sleeping well?
- Has there been a recent head injury?
- What medications does the person take?
- Does the person habitually use alcohol or drugs?
- What other symptoms are present?
Tests that may be done include:
Treatment depends on the underlying cause of the decreased consciousness. How well a person does depends on the cause of the condition. The longer the person has a decreased or altered level of consciousness, the worse the outcome.
A persistent coma is called vegetative state.
Blok BK, Newman TM. Syncope. In: Tintinalli JE, Kelen GD, Stapczynski JS, Ma OJ, Cline DM, eds. Emergency Medicine: A Comprehensive Study Guide. 6th ed. New York, NY: McGraw-Hill; 2004:chap 52.
Huff JS. Altered mental status and coma. In: Tintinalli JE, Kelen GD, Stapczynski JS, Ma OJ, Cline DM, eds. Emergency Medicine: A Comprehensive Study Guide. 6th ed. New York, NY: McGraw-Hill; 2004:chap 259.
Kirsch TD. Head injury. In: Tintinalli JE, Kelen GD, Stapczynski JS, Ma OJ, Cline DM, eds. Emergency Medicine: A Comprehensive Study Guide. 6th ed. New York, NY: McGraw-Hill; 2004:chap 255.
Review Date: 4/21/2009
Reviewed By: Jacob L. Heller, MD, Emergency Medicine, Virginia Mason Medical Center, Seattle, Washington, Clinic. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
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