Discover the causes, symptoms and treatment for benign and abnormal heart murmurs.

What are heart murmurs?

Heart murmurs can either be innocuous, or indicative of underlying heart conditions.

As Dr Jess John, a cardiologist at Mediclinic Panorama explains, valves keep blood moving through your heart in the right direction. When the heart valves are not functioning properly, it may cause a murmur. “A heart murmur is an extra sound that is caused by turbulent blood flow within the heart and occurs most commonly across heart valves,” he says. The murmur can be heard through a stethoscope as a "hum" or "whoosh" when blood flows through the heart. “Innocent heart murmurs, as the name suggests are benign and individuals may remain asymptomatic,” says Dr John. “However, pathological murmurs may result in symptoms. When symptoms are present, they might include fatigue or weakness; shortness of breath, especially during physical activity; chest pain or discomfort; a rapid or irregular heartbeat. Swelling in the abdomen, feet, or ankles can also occur.”

What causes heart murmurs?

Often found in children and adolescents, innocent (benign) murmurs are typically harmless. They result from normal blood flow patterns and the dynamic changes in blood flow that occur as the heart contracts and relaxes. Your healthcare provide will ascertain if there is any need for further tests or treatment. There is usually no need to restrict activities or stop playing sports.

Abnormal murmurs occur in children and adults and may be a sign of a more serious heart condition. They can be caused by a congenital defect (an abnormality present at birth) or heart valve disease. “Heart valves play a crucial role in ensuring one-way blood flow through the heart,” says Dr John. “If these valves become dysfunctional due to conditions like valve stenosis (narrowing) or valve regurgitation (leakage), abnormal blood flow can produce murmurs. The causes vary and can include age related degeneration of valves, infections affecting valves can cause inflammation and damage, leading to the development of murmurs. Active infection (infective endocarditis) and vegetations (growths) on the valve may be life-threatening. Abnormal connections between the chambers of the heart (both congenital or acquired) may also result in abnormal murmurs.”

How are heart murmurs diagnosed?

If your doctor suspects a heart murmur, further diagnostic tests may be ordered, including a transthoracic echocardiogram: This imaging test uses sound waves to create detailed images of the heart's structure and function, helping doctors visualise any abnormalities in the heart valves or chambers. An electrocardiogram (ECG or EKG): records the heart's electrical activity, helping detect irregular rhythms or other heart abnormalities. A chest X-ray will reveal the size and shape of your heart and blood vessels, providing additional insights into potential issues. Other more specialized tests include transoesophageal echocardiograms, cardiac computerized tomography (CT) or magnetic resonance imaging (MRI). Cardiac catheterisation (a test that looks at blood flow through the chambers and vessels around the heart) may also be used.

How are heart murmurs treated?

In some cases, a heart murmur may go away on its own. However, if an underlying problem or disease is causing the murmur, you may need treatment. This might include medication, surgery and /or changes to your lifestyle and diet, depending on the type and severity of the problem causing the murmur.

How to prevent heart murmurs

Adopting a heart-healthy lifestyle can significantly reduce the risk of developing conditions that may lead to murmurs. Dr John suggests the following steps:

  • Regular exercise: Engaging in regular physical activity promotes cardiovascular health and helps maintain optimal heart function.
  • Healthy diet: A balanced diet rich in fruits, vegetables, whole grains, lean proteins, and healthy fats supports heart health and reduces the risk of conditions that contribute to murmurs.
  • Regular check-ups: Routine medical check-ups can help detect and manage any potential heart issues before they escalate.
  • Blood pressure control: Keeping blood pressure within a healthy range is vital for preventing valve and vessel damage.
  • Smoking cessation: Quitting smoking reduces the risk of heart disease and improves overall cardiovascular health.

Disclaimer: The information provided in this article was correct at the time of publishing. At Mediclinic we endeavour to provide our patients and readers with accurate and reliable information, which is why we continually review and update our content. However, due to the dynamic nature of clinical information and medicine, some information may from time to time become outdated prior to revision.