For most people, heart murmurs, abnormal swishing sounds made by turbulent blood flow in the heart, are often harmless and don't require treatment. There are two types of heart murmurs: innocent, which often doesn't have any symptoms; and abnormal, which can cause shortness of breath, light-headedness, chest pain and palpitations (a rapid or irregular heartbeat).

In innocent heart murmurs, the heart muscle is normal, and the condition may disappear over time on its own, or it may linger for a lifetime without ever causing any health problems. Innocent heart murmurs are common in newborns and children-more than half of all children will have heart murmurs at some time.

An abnormal heart murmur is more serious. In children, it can be the result of congenital heart disease in which babies are born with structural heart defects, such as holes in the walls of the heart chambers (known as septal defects). It can also result from heart valve abnormalities in which not enough blood is getting through the valves or in which the valves don't close properly. In adults, abnormal heart murmurs are often due to heart valve problems.

Other causes of abnormal heart murmurs include:

  • Rheumatic fever
  • Endocarditis (an infection of the inner lining of the heart and valves)
  • Valve calcification (a hardening or thickening of the heart valves)
  • Mitral valve prolapse in which the valve between the heart's left upper chamber and left lower chamber doesn't close properly

Innocent heart murmurs can sometimes be the result of changes to the heart due to normal aging or heart surgery. They can also be the result of the following:

  • Anemia
  • Fever
  • Hyperthyroidism (an overproduction of the thyroid hormone)
  • Physical activity or exercise
  • Pregnancy


In innocent heart murmurs, treatment usually isn't necessary and may only be used when there is an underlying cause for the problem such as fever or hyperthyroidism. In those instances, the murmurs will go away once the condition has been successfully treated. Treatment for abnormal heart murmurs depends on the cause of the problem and may include:

  • Diuretics, to remove excess fluid from the body
  • Antibiotics, to prevent or treat endocarditis
  • Blood pressure medications to lower blood pressure
  • Statins to lower high cholesterol levels

To help reduce your risk for abnormal heart murmurs caused by heart valve disease:

  • Eat a low-fat diet
  • Exercise
  • Monitor your blood pressure