Loss of consciousness (unconsciousness)
When a person experiences a loss of consciousness, he or she is neither awake nor aware of the external environment. Loss of consciousness often is described as being "knocked out."
Attempts to arouse an unconscious person to an alert state may not be successful. The person may not respond at all or may respond with moans or nonpurposeful movements.
A loss of consciousness for longer than 60 seconds needs to be evaluated by a health professional.
Any loss of consciousness after a head injury, even if only for a short time, requires immediate evaluation by a health professional.
| 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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