Fainting

Temporary loss of consciousness due to reduced blood flow to the brain. 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. 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.