Syncope
According to the Heart Rhythm Society, syncope is a common problem that affects one million people in the U.S. every year. About one-third of us will faint at least once during our lifetime.

Syncope is the temporary loss of consciousness and posture, also known as fainting. It occurs when there is insufficient blood flow to the brain. The episode is usually brief (lasting less than a few minutes) and is followed by rapid and complete recovery. Fainting is fairly common, accounting for 6 percent of all emergency room visits and 3 percent of hospital stays.