General or Other | General Practice | Fainting (Symptom)
Fainting, blacking out, or syncope is the temporary loss of consciousness followed by the return to full wakefulness. This loss of consciousness may be accompanied by loss of muscle tone that can result in falling or slumping over.
Episodes of fainting are usually preceded by sweating, nausea, dizziness, and weakness, and are commonly caused by pain, stress, shock, a stuffy atmosphere, or prolonged coughing.
An episode may also result from postural hypotension, which may occur when a person stands still for a long time or suddenly stands up. This is common in the elderly, in people with diabetes mellitus, and in those on antihypertensive drugs or vasodilator drugs. Abdominal discomfort prior to loss of consciousness may be indicative of seizure which should be considered different than syncope.
In most cases, recovery from fainting occurs when normal blood flow to the brain is restored. This restoration usually happens within minutes because the loss of consciousness results in the person falling into a lying position, which restores the flow of blood to the brain. Medical attention should be sought for prolonged unconsciousness or repeated attacks of fainting. Although syncope may cause physical injury such as head trauma, it is specifically not directly caused by head trauma (concussion) or by a seizure disorder which may also produce short-lived unconsciousness unless these are also associated with globally reduced brain blood flow.