What is a heart murmur?

A heart murmur is a sound in your heart made by blood flowing through your heart and valves. The blood flow may be turbulent, which causes a blowing or whooshing sound your doctor can hear when they listen to your heart with a stethoscope.

Heart murmurs are common in babies and young children but can occur at any age. They can happen for many reasons, and not all are serious. Sometimes, though, a heart murmur can be a sign of a problem, such as a birth defect or an issue with your heart muscle or valves.

Types of heart murmurs

Heart murmurs can be divided into “innocent” (or normal) murmurs and murmurs related to heart problems, sometimes called abnormal or non-innocent heart murmurs.

Innocent heart murmurs are not a cause for concern and typically don’t need to be treated. They can be related to factors such as pregnancy, exercise or a child’s growth.

Heart murmurs that suggest a health issue are usually defined based on when the sound is heard:

  • Systolic murmur: This murmur occurs when your heart is pumping blood to the rest of your body.
  • Diastolic murmur: This murmur occurs when your heart muscle relaxes to fill up with blood. It’s often a sign of a heart valve issue.
  • Continuous murmur: This murmur occurs during your heart’s entire beat, when it’s pumping blood and when it’s relaxing.

Heart murmur symptoms

Heart murmurs generally do not cause symptoms if they’re innocent. Many conditions can cause heart murmurs, so symptoms can vary, but might include:

  • Blueness in face (in babies)
  • Chest pain (angina)
  • Difficulty during exercise or physical activity
  • Difficulty feeding (in babies and young children)
  • Dizziness
  • Excessive sweating while sitting or during gentle physical activity
  • Failure to thrive (in babies and children)
  • Fainting
  • Feeling lightheaded
  • Persistent cough
  • Rapid heartbeat or heart palpitations
  • Shortness of breath
  • Swelling in arms, legs or belly
  • Tiredness or fatigue

When to see a doctor

See a doctor if you experience symptoms that concern you.

You likely won’t be able to hear a heart murmur in yourself or your child. Doctors usually find them when listening to your heart through a stethoscope. Heart conditions can be serious, and early diagnosis and treatment are essential.

What causes a heart murmur?

Heart murmurs are caused by changes in your blood flow pattern or the function of your heart. Children often have innocent murmurs when their blood flows faster than normal due to exercise, growth spurts or other reasons. Adults can also be diagnosed with innocent murmurs.

Abnormal, or non-innocent, heart murmurs in adults are usually caused by heart diseases, while non-innocent heart murmurs in children may be caused by congenital heart defects. Heart murmurs can also develop from other health conditions, such as:

  • Anemia: A condition in which you have low red blood cell counts, anemia makes your blood less viscous, meaning it flows faster.
  • Congenital heart defects: These can affect the heart’s ability to pump, cause extra blood flow or allow blood to flow backward.
  • Endocarditis: This is an infection in the lining of your heart that can damage your heart valves.
  • Heart valve disease: Your heart’s four valves keep blood flowing in one direction. Valves may narrow (stenosis) or not close completely, allowing blood to flow backward (regurgitation).
  • Hypertrophic cardiomyopathy: This is a serious condition where part of your heart muscle becomes thickened, affecting normal blood flow.
  • Overactive thyroid: If your body produces too much thyroid hormone, this can increase your heart rate.

Heart murmur risk factors

Your risk of developing a heart murmur increases if you have any of the conditions known to cause murmurs. Additional factors that increase your or a child’s risk of developing a murmur include:

Age

Murmurs are common in the first year of life and during childhood. They often go away by age 14.

How is a heart murmur diagnosed?

Learning you have a heart murmur and whether it’s related to another health condition allows you to seek treatment for the underlying cause before the condition causes long-term problems.

Your doctor might hear a murmur when they listen to your or your child’s heartbeat with a stethoscope during a routine physical examination. If they think your murmur is a sign of underlying problems, they’ll order other tests that give them more information about your heart health.

Heart murmur treatments

An innocent heart murmur does not need treatment and normally goes away on its own. When treating non-innocent murmurs, doctors focus on the underlying cause. Because many different conditions can cause heart murmurs, your treatment will be tailored to your diagnosis.

Some heart conditions benefit from medication alone, while others need cardiac catheterization or surgery to limit their impact on your or your child’s health and well-being.

Medication

Medication can treat an underlying cause or control conditions, such as high blood pressure, that can worsen a heart murmur. Your doctor may also prescribe medication to address a possible complication, such as heart failure or arrhythmia, or an underlying cause.

Your doctor may recommend:

  • Angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers: These medicines work by opening your blood vessels and lowering your blood pressure, making it easier for your heart to pump blood.
  • Antiarrhythmic medications: These help restore your heart’s normal pumping rhythm.
  • Beta blockers: These slow your heart rate, reducing the strain on your heart.
  • Blood thinners: Faulty heart valves can increase your chance of dangerous blood clots linked to strokes. Blood thinners reduce this risk.
  • Diuretics: These drugs help your body get rid of excess fluid, lessening your heart’s workload.
  • Vasodilators: Vasodilators open and relax your blood vessels, making it easier to pump blood around your body.

Find specialized care for heart murmurs

At Baylor Scott & White, we have multiple locations across North and Central Texas to provide you with access to expert cardiology care. Our specialized cardiovascular centers are designed to meet the unique needs of people who have been diagnosed with a heart murmur. Whether you're seeking diagnostic testing, treatment options or need ongoing support, our teams are here to help you.

Frequently asked questions

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