Unconsciousness
A person who is unconscious is not aware of what is going on around him or her. He or she may not be able to make purposeful movements.
A person may become unconscious from an injury or a health condition.
- Fainting or a seizure disorder (epilepsy) may cause unconsciousness that is usually brief.
- Heart problems, such as stroke, heart attack, or changes in heart rate or rhythm (arrhythmia), can block blood and oxygen to the brain and cause unconsciousness.
- Lack of adequate oxygen, such as when there is too much carbon monoxide in the air a person breathes, can cause a gradual unconsciousness.
- Head injuries can "knock out" a person, making him or her unconscious.
- Any event that leads to being in a coma, which is a deep, prolonged state of unconsciousness. Diabetic coma, caused by very high or very low blood sugar, is one type of coma.
- Alcohol or drug abuse or withdrawal can cause the body to go into a state of shock that may cause unconsciousness. Heatstroke, an injury, or a traumatic event can also cause shock and unconsciousness.
| Author | Jeannette Curtis |
| Author | Caroline Rea, RN, BS, MS |
| Editor | Kathleen M. Ariss, MS |
| Editor | Susan Van Houten, RN, BSN, MBA |
| Associate Editor | Tracy Landauer |
| Associate Editor | Pat Truman |
| Primary Medical Reviewer | Patrice Burgess, MD - Family Medicine |
| Primary Medical Reviewer | Adam Husney, MD - Family Medicine |
| Primary Medical Reviewer | Kathleen Romito, MD - Family Medicine |
| Last Updated | May 25, 2007 |
WebMD Medical Reference from Healthwise
Last Updated:
May 25, 2007
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