What Is a Heart Murmur? Innocent Sounds vs Valve Disease

A heart murmur is an unusual sound heard between normal heartbeats. Many murmurs are harmless, but some are linked to heart valve problems or other conditions and should be checked by a doctor.

Overview

A heart murmur is an extra or unusual sound heard during a heartbeat, usually through a stethoscope. Instead of only the familiar “lub-dub” heart sounds, a doctor may hear a soft whooshing or swishing noise. This sound happens when blood flows through the heart or nearby blood vessels in a way that creates turbulence.

A murmur is not a diagnosis on its own. It is a clinical finding that can be completely harmless or can point to an underlying heart problem. Many children and healthy adults have what is called an innocent murmur, which does not damage the heart and often needs no treatment.

Other murmurs are related to structural heart changes, especially the heart valves. The valves help blood move in the right direction through the heart. If a valve is narrowed, stiff, or leaky, blood flow can become turbulent and create a murmur. This is why doctors look carefully at the cause rather than the sound alone.

Innocent Murmurs vs Valve Disease

An innocent heart murmur, sometimes called a functional or physiologic murmur, happens even though the heart is normal. These murmurs are especially common in children, teenagers, and young adults, but they can also occur in pregnancy or during times when blood flow is faster than usual, such as with fever or anemia. Innocent murmurs are usually soft, often change with body position, and do not cause symptoms.

A pathologic murmur suggests that there may be an underlying problem with the heart or circulation. One of the most common causes is heart valve disease, where a valve may be narrowed (stenosis) or may not close properly (regurgitation). Either problem can alter normal blood flow and produce a murmur.

Doctors also classify murmurs by when they occur in the heartbeat cycle. Systolic murmurs happen when the heart contracts, while diastolic murmurs happen when the heart relaxes. Some systolic murmurs are harmless, but diastolic murmurs are more often linked to structural heart disease and usually need further evaluation.

The presence of a murmur does not automatically mean serious illness. The overall picture matters, including the person’s age, symptoms, exam findings, medical history, and imaging results. A careful assessment helps separate harmless sounds from murmurs that need follow-up or treatment.

Symptoms and Signs

Many people with a heart murmur have no symptoms at all. The murmur may be found during a routine examination, a sports physical, a pregnancy checkup, or an assessment for another condition. Innocent murmurs usually do not cause shortness of breath, chest pain, fainting, or fatigue.

When a murmur is caused by heart disease, symptoms can vary depending on the problem and its severity. For example, valve disease may gradually reduce how effectively the heart pumps blood, or it may cause blood to flow backward. Over time, this can place extra strain on the heart and lungs.

Symptoms that may occur with a significant murmur include:

• Shortness of breath, especially with activity or when lying flat
• Chest discomfort or pressure
• Fatigue or reduced exercise tolerance
• Palpitations or a racing heartbeat
• Dizziness or fainting
• Swelling in the legs, ankles, or feet
• Bluish lips or fingertips in some infants or severe cases

Doctors also pay attention to associated signs, such as abnormal pulses, leg swelling, or evidence of fluid in the lungs. In babies and children, poor feeding, slow growth, heavy sweating during feeds, or rapid breathing may suggest that a murmur needs prompt evaluation.

Causes and Risk Factors

Heart murmurs can arise from normal blood flow, increased blood flow, or structural changes inside the heart. Innocent murmurs may occur when blood moves a little faster than usual through a healthy heart. This can happen during childhood, pregnancy, fever, exercise, anemia, or an overactive thyroid.

Abnormal murmurs often result from valve problems. A narrowed valve can make it harder for blood to pass through, while a leaky valve allows blood to flow backward. These changes may affect the aortic, mitral, tricuspid, or pulmonary valve. Over time, valve disease may develop due to aging, calcium buildup, prior infection, congenital abnormalities, or complications of other heart conditions.

Other causes include congenital heart defects present from birth, such as holes between heart chambers or abnormal valve structure. Inflammation or infection affecting the heart, including infective endocarditis, can also damage valves and create a murmur. Some murmurs are associated with cardiomyopathy, where the heart muscle becomes thickened or weakened.

Risk factors depend on the underlying cause but may include older age, a family history of valve or congenital heart disease, prior rheumatic fever, untreated infections, high blood pressure, and certain connective tissue disorders. People with known heart conditions should attend regular follow-up visits, as a new or changing murmur may signal progression.

How a Heart Murmur Is Diagnosed

Diagnosis starts with a medical history and physical examination. The doctor listens to the heart to assess where the murmur is heard best, how loud it is, and whether it occurs during systole or diastole. They may also ask about symptoms, exercise tolerance, pregnancy, fever, anemia, thyroid disease, and any past history of heart problems.

The most important test for many people is an echocardiogram, an ultrasound scan of the heart. This test shows the heart chambers, muscle function, and valves in motion. It helps doctors confirm whether the murmur is innocent or due to structural disease. In some cases, the doctor may also request an electrocardiogram, chest X-ray, or blood tests to look for contributing conditions such as anemia or infection.

If the cause appears to be valve-related, imaging helps define the type and severity of the problem. For example, echocardiography can show whether a valve is narrowed or leaking and how much strain it is placing on the heart. This information guides decisions about monitoring, medicines, or procedures. Patients who need more detailed evaluation may undergo advanced cardiac imaging or referral to a cardiologist for cardiology evaluation and care.

Not every murmur requires extensive testing. In a healthy child or adult with a typical innocent murmur and no concerning symptoms, a doctor may recommend observation alone. However, murmurs that are new, loud, associated with symptoms, or suggestive of valve disease usually deserve further assessment.

Treatment Options

Treatment depends entirely on the cause of the heart murmur. Innocent murmurs do not need treatment because the heart is normal. In these cases, the main goal is reassurance and routine care. Many children with innocent murmurs can stay active and do not need restrictions unless a doctor identifies another issue.

When a murmur is caused by another medical problem, treatment focuses on that condition. For example, correcting anemia, treating fever or infection, or managing thyroid disease may reduce or eliminate the murmur. If the cause is a heart rhythm issue or heart failure, medicines may be used to support heart function, control blood pressure, or reduce fluid buildup.

Valve disease may need ongoing monitoring or active treatment, depending on severity and symptoms. Some people do well for years with regular checkups and echocardiograms. Others may eventually need procedures to repair or replace a damaged valve. In selected cases, care may include heart valve surgery or less invasive catheter-based approaches such as TAVR for aortic valve disease.

If a murmur is linked to a congenital heart defect, management may range from observation to intervention. The right plan depends on the specific abnormality, symptoms, and age of the patient. A coordinated team can help determine whether treatment is needed now or whether careful follow-up is the safest approach.

Prevention and Self-care

Not all heart murmurs can be prevented, especially innocent murmurs or congenital conditions present from birth. However, some steps may lower the risk of developing valve damage or complications. Managing blood pressure, cholesterol, diabetes, and other cardiovascular risks supports long-term heart health.

Good dental hygiene and prompt treatment of infections can be important for some people, especially those with certain valve conditions, because infections can sometimes affect the heart valves. It is also helpful to follow a heart-healthy lifestyle with regular physical activity, a balanced diet, not smoking, and maintaining a healthy weight. These steps will not cure a structural murmur, but they can reduce strain on the heart.

People who already know they have a murmur should keep recommended follow-up appointments, even if they feel well. A doctor may repeat an echocardiogram over time to watch for changes. Patients should also ask whether they need any precautions before surgery, dental procedures, pregnancy, or strenuous exercise.

Near the end of the care journey, some patients benefit from specialist assessment in experienced centers. Acibadem International’s multidisciplinary specialists and JCI-accredited hospitals diagnose and treat heart conditions, including murmurs related to valve disease, for international patients when advanced evaluation is needed.

When to See a Doctor

A newly discovered heart murmur should be discussed with a doctor, especially if it is found in an adult, appears during pregnancy with symptoms, or is accompanied by shortness of breath, chest pain, palpitations, swelling, or fainting. Most murmurs are not emergencies, but they do deserve proper evaluation so the cause is clear.

Parents should seek medical advice if a baby or child has a murmur along with trouble feeding, poor weight gain, rapid breathing, bluish skin color, unusual tiredness, or reduced activity. In adults, a change in exercise tolerance, ankle swelling, or breathlessness can suggest progression of an underlying valve problem.

Urgent medical attention is important if symptoms are severe, sudden, or accompanied by signs such as chest pressure, fainting, severe shortness of breath, or confusion. These symptoms may not be caused by the murmur itself, but they can indicate a significant heart or circulatory problem.

Follow-up is especially important for anyone previously told they have valve disease, congenital heart disease, or a history of heart infection. Early assessment can help identify changes before complications develop and can support timely treatment if needed.

Frequently asked questions

Is a heart murmur always dangerous?

No. Many heart murmurs are innocent, meaning they are harmless sounds caused by normal blood flow through a healthy heart. A murmur becomes more concerning when it is linked to symptoms or an underlying heart condition, such as valve disease.

Can adults have innocent heart murmurs?

Yes. Although innocent murmurs are especially common in children, adults can also have them. Pregnancy, fever, anemia, and increased blood flow states can sometimes cause a harmless murmur in adulthood.

How do doctors tell if a heart murmur is serious?

Doctors begin with a physical examination and medical history, looking at the timing, loudness, and quality of the murmur. An echocardiogram is often the key test because it shows the heart valves and blood flow in real time.

Can a heart murmur go away on its own?

Some innocent murmurs can change over time or disappear, especially in children. A murmur caused by temporary factors such as fever or anemia may also improve once the underlying issue is treated.

What is the difference between a murmur and valve disease?

A murmur is a sound heard during the heartbeat, while valve disease is a structural problem affecting one or more heart valves. Valve disease can cause a murmur, but not every murmur means valve disease is present.

Can someone exercise with a heart murmur?

Many people with innocent murmurs can exercise normally. If a murmur is due to valve disease or another heart condition, a doctor may advise specific limits based on symptoms, test results, and overall heart function.

References

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

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.