Other conditions may cause symptoms similar to mitral valve prolapse.

Abnormal heart sounds that are heard through a stethoscope may be caused by:

• Conditions associated with the other heart valves (the aortic valve, pulmonic valve, or tricuspid valve).
• Rubbing between the heart and the sac (pericardium) around the heart.
• Hardening (calcification) of the mitral valve.
• Other causes of mitral valve leakage.

Chest pain may be caused by:

• Angina or heart attack caused by a decrease or lack of blood flow to the muscles of the heart.
• Injury to muscles, ligaments, or bones in the chest wall.
• Heartburn related to backflow of stomach acid into the tube (esophagus) from the mouth to the stomach (gastroesophageal reflux).
• Indigestion or stomach ulcers.
• Inflammation of the tissues surrounding the lungs (pleurisy) or the tissues surrounding the heart (pericarditis).
• Anxiety or panic attack.

Irregular heartbeat (arrhythmia) or pounding and racing of the heart (palpitations) may be caused by:

• Too much caffeine.
• Emotional stress.
• Irregularities in the heart rhythm.
• Heart disease related to not having enough blood flow to the muscles of the heart (ischemic heart disease).
• Heart defects present since birth (congenital defects).
• Abnormalities of the electrical system of the heart, such as Wolff-Parkinson-White syndrome.
• Scar tissue on the heart muscle from injury, infection, or other disease.
• Overactive thyroid gland (hyperthyroidism).
• An imbalance in the chemicals within the bloodstream.

Shortness of breath may be caused by:

• Asthma.
• Chronic lung disease.
• Being out of shape.
• A blockage of blood flow in the lungs (pulmonary emboli).

Fainting may be caused by:

• Inadequate blood volume due to dehydration.
• Arrhythmia.