[contentuser]

Causes and Risk Factors

Innocent heart murmurs can be caused by exercise, pregnancy, and fever. Aging and heart surgery can cause changes in the heart that may result in an innocent murmur. Other conditions that can cause innocent heart murmurs include anemia (low red blood cell count; lack of red blood cells to transport oxygen to other parts of the body) and hyperthyroidism (excessive production of thyroid hormone).

A number of medical conditions can cause abnormal heart murmurs. In chil...Read the full article