What Is a Heart Murmur?

A heart murmur is an unusual sound of blood flowing through the heart. When accompanied by other symptoms, such as shortness of breath or chest pain, it could be a sign of an underlying problem. But heart murmurs are often harmless and not related to other symptoms.

This article discusses heart murmur symptoms, potential complications, and signs that you should seek medical help.

Frequent Symptoms

A heart murmur is an extra "swooshing" noise as blood flows through the heart. You won't hear your heart murmur, and you likely won't feel it. But a healthcare provider can hear a murmur through a stethoscope.

Some heart murmurs are harmless. These are called innocent, benign, or functional. They don't cause any other symptoms.

Anything that increases the amount of blood that the heart is pumping can cause an innocent heart murmur. Increased blood flow can be associated with anxiety, fever, or exertion. These murmurs tend to clear up as soon as the trigger is gone. And otherwise, healthy children may eventually outgrow the heart murmur.

Other types of heart murmurs may be related to a heart condition. These heart conditions may cause a variety of symptoms, including:

• Occasional light-headedness or fainting
  
• Skipped heartbeats (palpitations)
  
• Feeling weak or tired
• Lower tolerance for physical activity
• Occasional shortness of breath
• Chronic cough
• Weight gain

Children and Heart Murmurs

Learning that your child has a heart murmur can be unsettling. But an innocent heart murmur in children is very common. Less than 1% of all pediatric heart murmurs are due to a heart defect. However, the murmur can be the first sign of cardiac disease.

Additional symptoms that suggest cardiac disease in children with heart murmur are:

• Skin that looks slightly blue (cyanosis)
• Excessive sweating
• Feeding problems
• Poor growth, poor weight gain, developmental delay
• Asthma-like symptoms
• Chest pain

Less Frequent Symptoms

Some symptoms in an individual with a heart murmur may indicate a severe and immediate health concern. These include:

• Trouble breathing
• Rapid heartbeat
• Chest pain
  
• Bulging neck veins
• Bluish skin
• Swelling of the feet, ankles, or abdomen
  

Complications

Innocent heart murmurs aren't associated with complications, but other heart murmurs are. Depending on the cause, these can include:

• Fainting: Although not always a sign of a serious condition, frequent fainting can be dangerous.
• Endocarditis: Infection to the heart valves, blood vessels, or the lining of the heart causes symptoms such as fever, chills, fast heart rate, fatigue, night sweats, aching joints and muscles, persistent cough, or swelling in the feet, legs, or abdomen. This type of infection can be challenging to treat.
• Blood clots: Symptoms vary depending on where they form but can include pain, tenderness, skin redness, breathing problems, and light-headedness. Without treatment, blood clots can be life-threatening.
• Stroke: Signs of a stroke may include a drooping face, arm weakness, and speech problems. Stroke is life-threatening and requires emergency medical care.
• Heart attack: A heart attack is when part of the heart doesn't get enough blood. Symptoms can include breathing problems, light-headedness, and pain in the chest, jaw, or arms.
• Heart failure: When your heart is too weak to pump enough blood throughout your body, it doesn't always cause noticeable symptoms at first. It can lead to shortness of breath, tiredness, and a buildup of fluids around the stomach, neck, or lower body.
• Sudden cardiac arrest: This means the heart has completely stopped.

When to See a Healthcare Provider

The only way to know you have a heart murmur is to listen through a stethoscope. See your healthcare provider as recommended if you've been told you have a heart murmur.

Abnormal heart murmurs can signify defective heart valves or other serious conditions. And if your child has congenital heart disease (heart disease dating from birth), a delayed diagnosis can increase the risk for morbidity and mortality.

Signs that you should call a healthcare professional are:

• You've had several instances of unexplained shortness of breath.
• You often feel light-headed or faint.
• Your heartbeat feels rapid or irregular.
• You have other new or unusual symptoms.

Seek immediate medical attention if you have warning signs of heart attack or stroke, such as:

• Chest pain or pressure that lasts more than a few minutes or comes and goes
• Pressure or pain involving the arms, neck, jaw, back, or stomach
• Breathing problems
• Cold sweat
• Nausea
• Light-headedness
• Face drooping
• Arm weakness
• Speech difficulty

Summary

Heart murmurs are abnormal heart sounds. They are often completely harmless, and benign heart murmurs are quite common in childhood. These heart murmurs are not associated with other symptoms. Heart murmurs can also signify a heart defect or heart disease. Some common heart murmur symptoms are heart palpitations, shortness of breath, or chest pains.

Potential complications include fainting, heart attack, and stroke. If you have any symptoms associated with heart problems, let your healthcare provider know or seek immediate medical attention.

A Word From Verywell

Many children and adults with a heart murmur live long and healthy lives. But knowing you or your child has a murmur can be upsetting. If you have any concerns at all, it's worth having a discussion with a healthcare professional. Find out if you need further screening for heart problems and if there are specific steps you can take to lower your risk of heart disease.