Fainting, sudden loss of consciousness followed by the return of wakefulness.
A loss of consciousness. Syncope is the medical term for fainting.
Transient loss of consciousness due to inadequate blood flow to the brain.
Fainting, lightheadedness.
A condition in which someone becomes unconscious for a short time because of reduced flow of blood to the brain.
Brief loss of consciousness due to temporarily insufficient flow of blood to the brain; it may be caused by injury, emotional shock, prolonged standing, or other events. In many cases the feeling is preceded by lightheadedness and can be prevented by sitting with the head between the knees. Also called fainting.
Loss of consciousness due to inadequate oxygen to the brain.
Loss of consciousness induced by a temporarily insufficient flow of blood to the brain. It commonly occurs in otherwise healthy people and may be caused by an emotional shock, by standing for prolonged periods, or by injury and profuse bleeding. An attack comes on gradually, with lightheadedness, sweating, and blurred vision. Recovery is normally prompt and without any persisting ill-effects.
Syncope, or fainting a loss of consciousness due to a fall in blood pressure. This may result because the cardiac output has become reduced, or because the peripheral resistance provided by the arterioles has decreased. The simple faint or vaso-vagal attack (so called because it is mediated by the vagus nerve which supplies the heart) is a result of a failure to maintain an adequate venous return of blood to the heart. This is likely to occur after prolonged periods of standing, particularly if one is standing still or if the climatic conditions are hot. It can also result from an unpleasant or painful experience. Pallor, sweating and a slow pulse are characteristic. Recovery is immediate when the venous return is restored by lying flat.
Transient (and usually sudden) loss of consciousness, accompanied by an inability to maintain an upright posture. Syncope occurs commonly; it results in about 1% to 6% of all hospital admissions in the U.S.
A transient period of unconsciousness resulting from a temporary deprivation of oxygen in the brain.
A brief loss of consciousness due to reduced blood flow to the brain, often referred to as fainting or swooning.