Heart Murmur Explained: Innocent Sounds vs Valvular Disease

A heart murmur is an extra or unusual sound heard between heartbeats. Many murmurs are harmless, but some may point to a heart valve problem or another condition that needs medical evaluation.

Overview: What a Heart Murmur Means

A heart murmur is an extra sound a doctor hears with a stethoscope as blood moves through the heart. Instead of only the usual “lub-dub” heartbeat, there may be a soft whooshing or swishing sound. A murmur can be heard in children or adults, and it can appear temporarily or be present over time.

Importantly, a heart murmur is not a disease on its own. It is a clinical finding that may be completely harmless or may suggest a problem affecting blood flow through the heart. The key question is whether the murmur is innocent or abnormal.

Innocent murmurs happen when blood flows a little faster or more turbulently through a normal heart. They are especially common in children, but they can also occur in adults during pregnancy, exercise, fever, or anemia. Abnormal murmurs are more concerning because they may be caused by heart valve disease, a congenital heart condition, or other structural changes in the heart.

The sound alone does not reveal the full story. A doctor considers where the murmur is heard, how loud it is, when it occurs during the heartbeat, and whether symptoms are present. This helps determine whether further testing is needed.

Innocent vs Abnormal Murmurs

An innocent heart murmur occurs in a structurally normal heart. These murmurs do not damage the heart and often do not require treatment. In children, they may come and go as the child grows. In adults, they can be related to temporary changes in circulation, such as pregnancy, fever, dehydration, or increased thyroid activity.

An abnormal murmur suggests that blood may be moving through a narrowed, leaking, or otherwise affected heart valve, or through an opening in the heart that should not be there. Common examples include aortic stenosis, mitral regurgitation, and congenital defects present from birth. In some people, the murmur is the first clue to heart valve disease.

Doctors often describe murmurs by timing. A systolic murmur happens when the heart contracts, while a diastolic murmur happens when the heart relaxes and fills. Diastolic murmurs are more likely to be abnormal and usually need further evaluation. Murmurs can also vary in pitch, loudness, and location on the chest.

Even when a murmur sounds mild, the overall assessment matters. A soft murmur in a healthy child with no symptoms is very different from a new murmur in an older adult with shortness of breath or chest discomfort.

Symptoms and Signs That May Occur

Many people with an innocent heart murmur have no symptoms at all. The murmur is often found during a routine checkup, sports physical, prenatal visit, or examination for another reason. In these cases, the person may feel entirely well.

When a murmur is related to an underlying heart problem, symptoms depend on the cause and severity. Possible symptoms include shortness of breath, unusual tiredness, dizziness, fainting, chest discomfort, palpitations, reduced exercise tolerance, or swelling in the legs and ankles. Babies and young children with significant heart problems may have poor feeding, sweating with feeds, bluish skin, or slow growth.

Some signs may suggest the murmur needs prompt medical attention. These include a new murmur along with breathlessness, fainting, rapid heartbeat, chest pain, or signs of heart failure. Fever plus a new murmur can sometimes raise concern for infection affecting the heart valves, especially in someone with known valve disease or certain risk factors.

Symptoms do not always match how loud a murmur sounds. A quiet murmur can still reflect an important heart condition, while a louder murmur may be innocent. That is why a full medical evaluation is important when there is any uncertainty.

Causes and Risk Factors

Innocent murmurs are caused by normal blood flow that becomes more audible under certain conditions. Faster blood flow can happen during childhood growth, exercise, pregnancy, fever, anemia, or an overactive thyroid. In these situations, the heart itself may be normal, and the murmur may lessen or disappear once the triggering factor resolves.

Abnormal murmurs are most often related to heart valves. A valve may be too narrow, called stenosis, which makes it harder for blood to pass through. A valve may also leak, called regurgitation or insufficiency, allowing blood to flow backward. Age-related calcium buildup, congenital valve differences, rheumatic heart disease, and infections can all affect valve function.

Other causes include congenital heart defects such as holes in the walls between heart chambers, thickened heart muscle as seen in hypertrophic cardiomyopathy, or changes in the heart after a heart attack. Sometimes a murmur can be associated with congenital heart disease that has not been detected earlier in life.

Risk factors for an abnormal murmur include older age, a family history of certain heart conditions, prior rheumatic fever, previous heart infection, long-standing high blood pressure, and known congenital abnormalities. Conditions outside the heart, such as severe anemia or hyperthyroidism, can also make a murmur more noticeable or uncover an underlying problem.

How Doctors Diagnose a Heart Murmur

Diagnosis begins with a medical history and careful physical examination. The doctor asks about symptoms, family history, childhood heart problems, infections, pregnancy, thyroid disease, and any changes in exercise tolerance. While listening with a stethoscope, the doctor notes the murmur’s timing, location, pitch, and intensity, and whether it changes with body position or breathing.

If the murmur appears innocent and there are no concerning signs, especially in a child, no treatment may be needed beyond routine follow-up. If the murmur is new, persistent, or suspicious for structural heart disease, the next step is usually an echocardiogram. This ultrasound test shows heart chambers, valves, blood flow, and pumping function in real time.

Other tests may also be helpful depending on the situation. These can include an electrocardiogram to look at the heart’s rhythm, a chest X-ray to assess heart size and lungs, blood tests for anemia or thyroid disorders, or exercise testing when symptoms appear with activity. In some cases, advanced imaging may be used to better define valve anatomy or congenital abnormalities.

For many patients, echocardiography provides the most important information because it can confirm whether the murmur is harmless or linked to a valve or structural problem. This helps guide the right follow-up and treatment plan.

Treatment Options and Follow-Up

Treatment for a heart murmur depends entirely on its cause. Innocent murmurs do not need medicines, procedures, or activity restrictions unless another condition is present. The focus is usually reassurance and periodic routine care.

If the murmur is due to an underlying condition outside the heart, treatment is aimed at that issue. For example, correcting anemia, treating fever, or managing thyroid disease may reduce or eliminate the murmur. When a murmur comes from valve disease, treatment may include medicines to ease symptoms or manage contributing problems such as high blood pressure, fluid buildup, or irregular heartbeat.

Some valve problems need ongoing surveillance, while others may eventually require an intervention. Depending on the valve involved and the severity of narrowing or leakage, treatment can include catheter-based procedures or surgery. In selected patients, doctors may discuss heart valve surgery if symptoms are significant or if tests show the heart is being affected.

People with complex findings may be referred to a cardiologist for long-term monitoring. In advanced cases, care may also involve specialists in cardiology and imaging to decide the safest timing for intervention. The goal is to protect heart function, relieve symptoms, and reduce complications while avoiding unnecessary treatment.

Prevention, Self-Care, and Living With a Murmur

Not all heart murmurs can be prevented, especially those caused by congenital conditions or age-related valve changes. Still, looking after overall heart health is valuable. This includes not smoking, staying physically active within a doctor’s advice, eating a balanced diet, managing blood pressure, diabetes, and cholesterol, and attending regular checkups.

Anyone with a known murmur should keep follow-up appointments, even if they feel well. If the doctor has identified a valve problem, periodic imaging may be recommended to watch for changes. New symptoms such as increasing breathlessness, fatigue, ankle swelling, or fainting should be reported promptly.

Good dental care is also important because oral infections can sometimes affect heart valves in vulnerable people. Not everyone with a murmur needs antibiotics before dental work; this is only advised for certain high-risk heart conditions. A doctor can explain whether any precautions apply.

For international patients who need evaluation or treatment, Acibadem International’s multidisciplinary specialists and JCI-accredited hospitals provide assessment and care for heart valve and related cardiac conditions.

When to See a Doctor

A person should arrange a medical evaluation if a doctor has newly detected a heart murmur, especially if there are symptoms or a history of heart disease. Murmurs in newborns, infants, and older adults are more likely to require closer assessment than a typical innocent murmur in a healthy child.

Medical attention is especially important if the murmur is accompanied by shortness of breath, chest pain, fainting, bluish lips or fingertips, swelling in the legs, rapid or irregular heartbeat, or unexplained fatigue. In children, feeding difficulty, poor weight gain, or tiring easily with activity should also be checked.

Urgent care is needed for severe chest pain, sudden difficulty breathing, fainting, or signs of stroke. Fever together with a new murmur, particularly in someone with known valve disease, an artificial valve, or recent infection, should also be assessed without delay.

Early evaluation helps distinguish a harmless sound from a condition that needs monitoring or treatment. In many cases, timely testing provides reassurance; in others, it helps start the right care before complications develop.

Frequently asked questions

Is a heart murmur always serious?

No. Many heart murmurs are innocent, which means the heart is structurally normal and the sound is harmless. A doctor still needs to assess the murmur to determine whether it is innocent or related to an underlying condition.

Can adults develop a heart murmur later in life?

Yes. Adults can develop a new heart murmur because of valve changes, anemia, fever, pregnancy, thyroid disease, or other conditions that affect blood flow. A new murmur in adulthood should usually be evaluated, especially if symptoms are present.

How is a heart murmur confirmed?

A doctor first detects it during a physical examination with a stethoscope. If more information is needed, an echocardiogram is commonly used to look at the heart valves, chambers, and blood flow.

Can a heart murmur go away on its own?

Some innocent murmurs can fade or disappear over time, especially in children. Murmurs related to temporary conditions such as fever or anemia may also improve when the underlying cause is treated.

Can someone exercise if they have a heart murmur?

Often yes, especially if the murmur is innocent and there is no heart disease. If the murmur is caused by a valve problem or another heart condition, a doctor may recommend specific activity guidance based on symptoms and test results.

Do all heart murmurs need treatment?

No. Innocent murmurs do not require treatment. Treatment is only needed when the murmur is due to an underlying problem, and the approach depends on the exact cause and severity.

References

• American Heart Association
• National Heart, Lung, and Blood Institute
• European Society of Cardiology
• Centers for Disease Control and Prevention
• Merck Manual Consumer Version

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.