Mitral valve prolapse is a common, and usually not serious, heart condition affecting 2 - 5 percent of the population. It is caused by a fairly minor abnormality of the heart valve -- a gate-like structure that opens and closes -- between the upper chamber (atrium) and lower chamber (ventricle) on the left side of the heart. As the heart contracts, this valve normally closes all the way. But in mitral valve prolapse, the cusps, or open edges of the valve, collapse into the left atrium. Sometimes, small amounts of blood can be leaked back into the atrium and cause mitral valve regurgitation, a sound commonly known as a heart murmur.

A doctor diagnoses mitral valve prolapse after hearing the characteristic clicking sound through a stethoscope. Echocardiography, an imaging technique that uses ultrasound waves, allows the doctor to view the prolapse and determine if the regurgitation is severe.

Most people with mitral valve prolapse have no symptoms. Others may have a spectrum of symptoms: chest pain, heart palpitations, migraine headaches, fatigue, gastrointestinal discomfort, and dizziness. People with mitral valve prolapse often feel very anxious, sense strongly that "something is wrong," have trouble sleeping, and even experience panic attacks. Premenstrual syndrome is a common finding among women with this disorder.

Some researchers believe that mitral valve prolapse is a condition "waiting to happen." The right "trigger" is often a period of stress. If no other serious condition is found to be responsible for the symptoms, most people with this heart condition just need reassurance and perhaps a sympathetic ear.

Medications, however, can sometimes be beneficial. If the heart is beating too fast, a beta-blocker may help slow the heart rate and reduce palpitations; other types of medications may also be prescribed for different symptoms. Regular exercise, avoidance of caffeine, high fluid intake, and avoidance of sweet snacks (to normalize blood sugar) can also help. For people with regurgitation, antibiotics are prescribed before surgery and dental procedures to prevent bacteria from infecting the heart.