When is fainting dangerous, and what should I do?
Fainting is brief loss of consciousness and can have reflex or blood-pressure causes, but assessment helps identify why it happened. Events during exercise or while lying down, chest pain, palpitations, injury or failure to regain consciousness promptly are concerning.
Details
Start with responsiveness and breathing
If the person is unresponsive or not breathing normally, call emergency services immediately and follow dispatcher resuscitation instructions. Do not give food or water to someone not fully alert. Help a conscious person feeling faint to lie down safely.
Signs requiring emergency help
Call for help if recovery is not prompt, speech or movement is impaired, chest pain or breathlessness occurs, or there is serious injury. Do not assume jerking or recurrent unconsciousness is merely tiredness.
After recovery
Record preceding events, duration, witness observations and medicines. ECG or further assessment may be needed. Avoid driving or working at height with unexplained or repeated fainting until appropriate medical guidance is given.
Related reading: Why do I feel dizzy when standing up, and when should it be checked?.