Heart murmurs are sounds — such as whooshing or swishing — made by rapid, choppy (turbulent) blood flow through the heart. The sounds can be heard with a device called a stethoscope. A typical heartbeat makes two sounds like "lubb-dupp" (sometimes described as "lub-DUP") when the heart valves are closing.

Heart murmurs can be present at birth (congenital) or develop later in life (acquired).

Some heart murmurs are harmless (innocent). An innocent heart murmur is not a sign of heart disease and doesn't need treatment. Other heart murmurs may be a sign of a serious heart condition. Tests are needed to check the heart and heart valves. Heart murmur treatment depends on the cause.

Harmless (innocent) heart murmurs usually don't cause any other symptoms.

Symptoms of worrisome heart murmurs depend on the cause. Heart murmur symptoms may include:

• Blue or gray fingernails or lips
• Chest pain
• Cough that doesn't go away
• Dizziness
• Swollen liver
• Swollen neck veins
• Fainting
• Heavy sweating with little or no activity
• In infants, poor appetite and lack of growth
• Shortness of breath
• Swelling or sudden weight gain

Most heart murmurs aren't serious. If you're concerned about a heart murmur, make an appointment to see your primary care provider. Your provider can tell you if follow-up care is needed.

A heart murmur is caused by rapid, choppy (turbulent) blood flow through the heart. A heart murmur may happen:

• When the heart is filling with blood (diastolic murmur)
• When the heart is emptying (systolic murmur)
• Throughout the heartbeat (continuous murmur)

Harmless (innocent) heart murmurs

A person with an innocent murmur usually has a typical heart. Innocent heart murmurs are common in newborns and children.

Things that might change blood flow and cause an innocent heart murmur include:

• Fever
• Lack of healthy red blood cells that carry oxygen to body tissues (anemia)
• Overactive thyroid (hyperthyroidism)
• Phases of rapid growth, such as adolescence
• Physical activity or exercise
• Pregnancy

Innocent heart murmurs may go away over time. Sometimes, heart murmurs continue for life without causing serious health problems.

Worrisome heart murmurs

In children, worrisome murmurs are usually due to a problem with the heart's structure that's present at birth (congenital heart defect).

Congenital causes of worrisome heart murmurs include:

• Holes in the heart. A hole may form before birth in the wall between the upper or lower heart chambers, or both. Examples are atrial septal defect and ventricular septal defect.
• Cardiac shunts. A heart structure problem present before birth (congenital heart defect) causes irregular blood flow between the heart chambers or blood vessels.

In adults, worrisome heart murmurs are usually due to heart valve problems that develop later in life (acquired heart valve disease). Things that can damage the heart valves include:

• Calcium deposits. Calcium deposits can cause a heart valve — such as the mitral valve or the aortic valve — to become stiff and narrow (valve stenosis). A calcified valve also may not close completely, letting blood flow backward. The changes in blood flow create a murmur. When calcium affects the heart valves, it's called calcific or degenerative valve disease.
• Infection of the inner heart lining and valves (endocarditis). Bacteria or other germs cause this infection. The germs spread through the blood to the heart from another part of the body, such as the mouth. A murmur may occur if the infection is untreated and affects the heart valves.
• Rheumatic fever. This is a serious complication of strep throat. It's rare in the United States. Rheumatic fever may occur in those who don't get or complete treatment for strep throat. When rheumatic fever affects the heart valves, it's called rheumatic heart disease. A heart valve problem can cause a murmur.

Things that increase the risk of heart murmurs in babies includes:

• Family history of heart problems linked to murmurs
• Uncontrolled diabetes in the mother during pregnancy
• German measles (rubella) in the mother during pregnancy
• Use of certain medications, alcohol or illegal drugs by the mother during pregnancy

Some medical conditions can increase the risk of heart murmurs, including:

• A rare cancerous tumor that releases certain chemicals into the bloodstream (carcinoid syndrome)
• A weakened heart muscle (cardiomyopathy)
• An infection of the lining of the heart (endocarditis)
• Anemia
• Blood disorders marked by a high number of certain white cells, called eosinophils (hypereosinophilic syndrome)
• Certain autoimmune disorders such as lupus and rheumatoid arthritis
• Heart valve disease
• High blood pressure in the lungs (pulmonary hypertension)
• History of rheumatic fever
• Overactive thyroid (hyperthyroidism)

There's no known prevention for heart murmurs. But healthy lifestyle changes can improve heart health and prevent some conditions linked to murmurs in adults. Many childhood heart murmurs go away on their own as children grow.

Heart murmurs may be detected when a physical exam is done for another reason. You'll be asked questions about your personal and family medical history.

A health care provider can listen to the heart using a device called a stethoscope. The provider considers several things when listening to the heart to tell if a murmur is innocent or worrisome. Some of those things are:

• Volume. How loud is the heart murmur on a scale from 1 to 6? The loudest heart murmur is 6.
• Location. Where in the heart is it? Does the sound spread to the neck or back?
• Pitch. Is it high-, medium- or low-pitched?
• Timing of the murmur. A murmur that occurs when blood leaves the heart (systolic murmur) generally is an innocent heart murmur. One that happens when the heart fills with blood (diastolic murmur) or throughout the heartbeat (continuous murmur) may signal a heart problem.
• Sound changes. Does exercising or changing body position affect the sound?

Tests

Tests are done to determine the cause of worrisome heart murmurs. Heart murmur tests may include:

• Echocardiogram. This is the main test used to determine the cause of a heart murmur. An echocardiogram uses sound waves to create pictures of the beating heart. It shows how blood flows through the heart and heart valves.
• Chest X-ray. A chest X-ray is a picture of the heart and lungs. It can tell whether the heart is enlarged. Heart enlargement may cause some heart murmurs.
• Electrocardiogram (ECG or EKG). This quick and painless test measures the electrical activity of the heart. During an ECG, sensors (electrodes) are attached to the chest and sometimes to the arms or legs. Wires from the sensors connect to a machine, which prints or displays results. A health care provider can look at the signal patterns for signs of heart problems.
• Cardiac catheterization. This test may be done when other tests haven't found a cause for the heart murmur. A heart doctor (cardiologist) inserts a flexible tube (catheter) into a blood vessel, usually in the groin or wrist. The catheter is gently guided to the heart. Dye may be injected through the catheter. The dye helps blood vessels show up better on the images made during the test.

Innocent heart murmurs don't usually need treatment. If a fever or an overactive thyroid (hyperthyroidism) causes a murmur, the murmur usually goes away once that condition is treated.

Treatment for a worrisome heart murmur depends on cause. A worrisome heart murmur requires close monitoring by a health care provider. Medications or surgery may be needed.

Medications

Medications that might be used to treat heart conditions associated with murmurs include:

• Blood thinners (anticoagulants). This type of medicine prevents blood clots. Some conditions that cause heart murmurs are closely linked to irregular heartbeats (arrhythmias) that can cause blood clots. Blood clots increase the risk of strokes. Blood thinners include warfarin (Jantoven), clopidogrel (Plavix), apixaban (Eliquis), rivaroxaban (Xarelto), dabigatran (Pradaxa) and others.
• Water pills (diuretics). This medicine removes excess fluid from the body. A diuretic may be given to treat high blood pressure or other conditions that can make heart murmurs worse.
• Angiotensin-converting enzyme (ACE) inhibitors. This type of drug lowers blood pressure. High blood pressure can worsen underlying conditions that cause heart murmurs.
• Beta blockers. A beta blocker lowers heart rate and blood pressure.

In the past, many people with worrisome heart murmurs were told to take antibiotics before surgery or dental procedures to prevent certain heart infections. That recommendation has changed. Antibiotics are only recommended in specific situations. For instance, they may be recommended for people with artificial heart valves, a history of heart valve infections or congenital heart defects that increases the risk of infection inside the heart.

Surgery or other procedures

Surgery may be needed to correct a condition that causes a worrisome heart murmur.

For example, if a narrowed or leaky heart valve is causing the murmur and other symptoms, heart valve repair or replacement may be needed.

During heart valve repair, a surgeon might:

• Patch holes in a valve
• Separate valve leaflets that have fused
• Replace the cords that support the valve
• Remove excess valve tissue so that the valve can close tightly
• Tighten or reinforce the ring around a valve

Heart valve surgery may be done as:

• Open-heart surgery
• Minimally invasive heart surgery
• Robotic heart surgery
• A procedure using flexible tubes (catheter procedure)

The way the surgery or procedure is done depends on the specific heart condition.

If you're concerned about a heart murmur, make an appointment to see your family care provider. Although most heart murmurs are harmless, it's a good idea to check for any underlying heart problems that could be serious. You may be referred to a doctor that specializes in heart diseases (cardiologist).

Appointments can be brief. So it's a good idea to be prepared for your appointment. Here's some information to help you get ready and know what to expect from your health care provider.

What you can do

• Be aware of any pre-appointment restrictions. Ask if there's anything you need to do before your appointment. For example, if you're having a certain type of echocardiogram, you may need to avoid food or drink for several hours before the test.
• Write down any symptoms, including any that may seem unrelated to heart murmurs.
• Write down your family medical history, including a family history of heart murmurs, heart rhythm problems, heart defects, coronary artery disease, genetic disorders, stroke, high blood pressure or diabetes.
• Write down any major stresses or recent life changes.
• Make a list of all current medications, vitamins or supplements that you or your child is taking. Include the dosages.
• Take a family member or friend along, if possible. Sometimes it can be difficult to remember all information provided to you during an appointment. Someone who comes along with you may remember something that you missed or forgot.
• Be prepared to discuss diet and exercise habits. If you or your child doesn't already follow a diet or exercise routine, be ready to talk to your care provider about any challenges you might face in getting started.

Time with a health care provider is limited. Preparing a list of questions can help you make the most of your time together. For heart murmurs, some basic questions to ask your provider include:

• What's the most likely cause of the heart murmur?
• What are other possible causes for the heart murmur?
• What kinds of tests are necessary?
• What's the best treatment or follow-up care?
• What are the alternatives to the primary approach that you're suggesting?
• How should health conditions other than the heart murmur be managed?
• Are there any dietary or exercise restrictions that I need to follow?
• Should I see a specialist?
• If surgery is necessary, which surgeon do you recommend?
• Is there a generic alternative to the medicine you're prescribing?
• Are there any brochures or other printed material that I can take home with me? What websites do you recommend visiting?

What to expect from your doctor

Your health care provider is likely to ask you a few questions. Being ready to answer them may save time to go over any details you want to spend more time on. Your provider may ask:

• What are the symptoms? Include any history of fainting, chest pain, leg swelling, skin color changes and shortness of breath.
• When did the symptoms start?
• Are the symptoms constant or do they come and go?
• How severe are the symptoms?
• What, if anything, seems to make the symptoms better?
• Does anything make the symptoms worse?
• Have you ever used illegal drugs?
• Is there a history of rheumatic fever?
• Does anyone else in the family have a heart murmur or a heart valve problem?