What Is a Heart Murmur? Causes and When It Needs Testing

A heart murmur is an extra sound heard during the heartbeat, often described as a whooshing noise. Many murmurs are harmless, but some can signal an underlying heart problem that should be assessed with the right tests.

Overview: What Is a Heart Murmur?

A heart murmur is an extra sound heard when a doctor listens to the heart with a stethoscope. Instead of only the usual “lub-dub” heart sounds, there may be a soft blowing, swishing, or whooshing noise. This sound happens because blood flow becomes more turbulent than usual as it moves through the heart or nearby blood vessels.

A murmur itself is not a diagnosis. It is a clinical finding that can be completely harmless or can point to a structural heart issue that needs more attention. For this reason, a heart murmur is best understood as a clue that helps guide the doctor toward whether further assessment is needed.

Heart murmurs can occur in babies, children, and adults. In many children and some adults, the murmur is “innocent,” meaning the heart is normal and the sound reflects blood flowing normally through a healthy heart. In other cases, a murmur may be related to conditions affecting the heart valves, the heart muscle, or holes in the heart present from birth.

Doctors often classify murmurs by when they happen during the heartbeat, how loud they are, and where they are heard best. These details help determine whether the murmur is likely harmless or whether it may be related to conditions such as heart valve disease.

Symptoms: Does a Heart Murmur Cause Problems?

Many people with a heart murmur have no symptoms at all. Innocent murmurs usually do not cause discomfort, limit activity, or affect long-term health. Often, they are found incidentally during a routine check-up, sports examination, pregnancy visit, or evaluation for another concern.

When a murmur is related to an underlying heart condition, symptoms depend on the cause and its severity. A person may notice breathlessness during activity or at rest, unusual tiredness, dizziness, fainting, chest discomfort, or a fast or irregular heartbeat. Some people develop swelling in the legs, ankles, or abdomen if the heart is under strain.

In infants and children, warning signs may include poor feeding, sweating during feeds, slow weight gain, rapid breathing, or a bluish color around the lips or skin. These signs do not always mean a serious condition is present, but they should be assessed promptly by a doctor.

• Shortness of breath
• Chest pain or pressure
• Fainting or near-fainting
• Palpitations
• Swelling in the legs or abdomen
• Blue-tinged lips or skin
• Reduced exercise tolerance

Causes and Risk Factors

Heart murmurs are commonly divided into innocent and abnormal murmurs. Innocent murmurs happen when blood moves quickly through a normal heart. This may occur in children, during pregnancy, after exercise, or with temporary conditions such as fever or anemia. These murmurs are usually soft and do not reflect heart disease.

Abnormal murmurs can be caused by structural changes in the heart. One common reason is a valve problem, such as a valve that is narrowed and does not open fully, or a valve that does not close tightly and allows blood to leak backward. These conditions can affect the aortic, mitral, tricuspid, or pulmonary valves and may develop with age, infection, calcium buildup, or rheumatic heart disease.

Some murmurs are due to congenital heart defects, meaning changes in heart structure present from birth. Examples include holes between heart chambers or abnormalities in blood vessels leaving the heart. In adults, other causes may include an enlarged heart muscle, high blood pressure affecting the heart, or changes after a heart attack. A murmur may sometimes be associated with congenital heart disease or other cardiovascular conditions.

Factors that can increase the chance of an abnormal murmur include older age, family history of certain heart conditions, a history of heart infection, untreated high blood pressure, autoimmune disease, or previous radiation to the chest. People with risk factors do not always develop a serious problem, but regular follow-up can help detect changes early.

How Doctors Diagnose a Heart Murmur

Diagnosis begins with a medical history and physical examination. The doctor listens carefully to the heart, noting when the murmur occurs in the heartbeat, how loud it is, whether it changes with body position, and whether there are other unusual heart sounds. They also ask about symptoms, exercise tolerance, family history, past illnesses, and any known heart conditions.

If the murmur appears clearly innocent and there are no symptoms or concerning findings, no further testing may be needed. If the murmur sounds abnormal, is newly detected in an adult, or is accompanied by symptoms, the doctor may order tests to understand the cause. The most important test is usually an echocardiogram, an ultrasound scan that shows heart chambers, valves, and blood flow in real time. This is often part of echocardiography when assessing a murmur.

Other tests may help depending on the situation. An electrocardiogram records the heart’s electrical activity, while a chest X-ray can show heart size and lung changes. Blood tests may look for anemia, infection, thyroid problems, or other contributing conditions. Some people also need exercise testing, ambulatory rhythm monitoring, or more advanced imaging such as cardiac MRI if the diagnosis remains unclear.

The goal of testing is not only to confirm whether a murmur is harmless or abnormal, but also to measure how any underlying condition is affecting heart function. This helps guide treatment and follow-up in a safe, individualized way.

Treatment Options and Follow-Up

Treatment depends entirely on the cause. Innocent murmurs do not need medicine, surgery, or activity restrictions in most cases. Reassurance is often all that is needed, although the doctor may continue to listen to the heart during routine visits.

If a murmur is caused by another medical problem, treatment focuses on that issue. For example, managing anemia, controlling high blood pressure, or treating thyroid disease may reduce the conditions that contribute to turbulent blood flow. If the murmur is related to a heart rhythm problem or heart muscle disease, a cardiologist may recommend medications or ongoing monitoring.

When a murmur is due to valve disease, treatment depends on how severe the valve problem is and whether symptoms are present. Some people need periodic imaging and observation only. Others may need medication to ease symptoms or procedures to repair or replace a diseased valve. In selected cases, doctors may consider heart valve surgery or minimally invasive approaches after a full cardiology evaluation.

Children and adults with congenital causes may need specialized follow-up, sometimes with repeat echocardiograms over time. Acibadem International’s multidisciplinary specialists in JCI-accredited hospitals evaluate and treat heart murmurs and related conditions for international patients when more detailed assessment is required.

Prevention and Self-Care

Not all heart murmurs can be prevented, especially those caused by congenital heart changes or age-related valve problems. Still, overall heart health can lower the risk of some underlying conditions that may lead to abnormal murmurs or make existing heart disease worse.

Helpful self-care steps include managing blood pressure, cholesterol, diabetes, and body weight; staying physically active within a doctor’s advice; not smoking; and eating a balanced diet rich in vegetables, fruits, whole grains, and lean protein. Limiting excess alcohol and keeping regular medical appointments are also important.

People who already know they have a murmur should follow their doctor’s plan for monitoring. It can help to keep track of symptoms such as breathlessness, reduced exercise capacity, chest discomfort, or swelling. Any change in symptoms should be reported, even if previous tests were reassuring.

Good dental hygiene is also important because some heart conditions can increase the risk of heart valve infection. A doctor can explain whether any special precautions are needed before dental or surgical procedures, as recommendations vary depending on the specific heart condition.

When a Heart Murmur Needs Testing

A heart murmur often needs testing when it is newly discovered in an adult, sounds clearly abnormal, or occurs along with symptoms. Doctors are especially more likely to investigate if there is shortness of breath, chest pain, fainting, palpitations, cyanosis, leg swelling, or signs of heart failure. Testing is also more important when there is a history of valve disease, congenital heart disease, or infection that could affect the heart.

In babies and children, urgent evaluation is needed if the child has trouble feeding, poor growth, blue skin color, unusual sleepiness, rapid breathing, or sweating with feeds. In adults, sudden worsening fatigue or exercise intolerance should not be ignored. While many murmurs remain harmless, new symptoms can suggest that the heart is working harder than it should.

Even when symptoms are mild, it is wise to seek advice if a murmur has not been assessed before. Early evaluation can identify treatable conditions before they lead to complications. If the doctor suspects a significant structural problem, referral to a cardiologist and targeted testing such as a cardiology check-up can clarify the next steps.

Emergency care is important if a person develops severe chest pain, major breathing difficulty, faints, or shows signs of poor circulation. These symptoms do not always come from a murmur itself, but they always deserve prompt medical attention.

Frequently asked questions

Is a heart murmur always serious?

No. Many heart murmurs are innocent, especially in children and younger adults, and do not mean there is heart disease. A doctor can usually decide whether the murmur sounds harmless or whether further testing is needed.

Can adults develop a heart murmur later in life?

Yes. A new heart murmur in adulthood can appear because of changes in the heart valves, anemia, fever, pregnancy, or other medical conditions. Since new murmurs in adults are more likely to need assessment, a medical review is important.

What test is most commonly used to check a heart murmur?

The most common test is an echocardiogram. This ultrasound exam shows the heart's structure, valve movement, and blood flow, helping doctors tell whether the murmur is innocent or related to an underlying problem.

Can a heart murmur go away on its own?

Some can. Innocent murmurs may become less noticeable over time, especially in children, or disappear when a temporary cause such as fever or anemia improves. Murmurs caused by structural heart disease usually do not go away unless the underlying condition is treated.

Should someone with a heart murmur avoid exercise?

Not necessarily. People with innocent murmurs can usually stay active without restrictions, while those with an abnormal murmur may need advice tailored to their diagnosis. A doctor or cardiologist can explain what level of exercise is safe.

What symptoms mean a heart murmur should be checked soon?

Shortness of breath, chest pain, fainting, swelling in the legs, a bluish color to the lips or skin, or a marked drop in exercise tolerance should be assessed promptly. In babies, poor feeding, sweating during feeds, and poor weight gain also need timely evaluation.

References

• American Heart Association
• National Heart, Lung, and Blood Institute
• Mayo Clinic
• NHS
• European Society of Cardiology

This article is for general information only and is not a substitute for professional medical advice. Please consult a qualified doctor about your individual situation.