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Home > Wellness > Health Library > 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
A loss of consciousness for longer than 60 seconds needs to be
evaluated by a doctor.
Any loss of consciousness after a head injury, even if only for a
short time, requires immediate evaluation by a doctor.
Current as of:
September 9, 2014
William H. Blahd, Jr., MD, FACEP - Emergency Medicine & H. Michael O'Connor, MD - Emergency Medicine
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