A heart murmur is a sound made by turbulent blood flow in the heart. It sounds like whooshing or swishing with each heartbeat. Some adults and many children have incidental heart murmurs that are benign (harmless) and are not caused by abnormalities in the heart. At least 30% of children may have an innocent heart murmur at some point during childhood. However, some heart murmurs can signal an underlying heart problem.
Heartbeat: Anatomy of the Heart
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Benign murmurs are caused by the normal flow of blood through the heart and large vessels near the heart. The murmur may come and go over time. Some things that can increase blood flow and cause a benign heart murmur to be heard include:
Abnormal heart murmurs can be due to:
- Structural abnormalities of the heart valves (most common)—these may be congenital (present from birth) or acquired later in life. Examples include:
- Abnormal holes or connections in the structure of the heart or vessels persisting after birth:
- Structural abnormality of the heart muscle:
- Other congenital heart conditions, such as:
- Endocarditis —infection of the inner lining of heart valves and chambers (endocardium)
- Cardiac myxoma—a benign soft tumor within the heart (rare)
Last reviewedSeptember 2013by Marcin Chwistek, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.