Fainting

Fainting is common in humans because the brain resides far above the source of its blood supply (the heart). Any abrupt drop in blood pressure can lead to a faint. Fortunately, the cause is often innocent, and recurrence is infrequent. However, a faint may warn of serious underlying heart disease. In many patients, the physician can distinguish between innocent and serious situations by taking a detailed medical history, carefully reviewing the circumstances of the faint(s), examining the fainter, and perhaps obtaining a heart tracing (ECG) and/or a painless heart imaging test (echocardiogram). On occasion, additional medical tests are needed. Overall, in 80% to 90% of fainters, a likely cause can be established and effective treatment initiated.