Syncope is the loss of consciousness and posture that is usually caused by a temporary lack of sufficient blood flow to the brain, according to the American Heart Association. This insufficient blood flow normally occurs when blood pressure is too low and the heart does not pump enough oxygen to the brain.
Syncope is caused by overheating, dehydration, heavy sweating and exhaustion, reports the American Heart Association. People with cardiac, neurologic, psychiatric, metabolic and lung disorders also experience syncope. If syncope occurs during exercise, includes palpitations of the heart or is recurrent, there may be a more serious underlying issue.
Neurally mediated syncope is the most frequent type and is not life-threatening. It is most common in children and young adults, and it is evaluated by checking the blood pressure and heart rate while standing and lying down. Neurally mediated syncope occurs when blood pressure drops quickly, causing a reduction in blood supply to the brain. A feeling of warmth, nausea, lightheadedness and graying of the visual field are commonly noticed when syncope is about to occur, states the American Heart Association. People diagnosed with neurally mediated syncope should try high-salt diets, avoid dehydration, and sit or lie down if they feel any of the warning signs of syncope.
If the syncope may be related to heart problems, a physician may recommend an exercise stress test, a Holter monitor test, an electrocardiogram or an echocardiogram. The electrocardiogram checks for abnormal heart rhythms that are related to genetic heart conditions. Some genetic heart conditions that cause syncope also cause sudden cardiac death, so patients must follow through with testing recommendations made by a physician, warns the American Heart Association.