Everything a Parent Should Know About a Child’s Heart Murmur

By: Peter R. Koenig, MD
November 25, 2019

The term heart murmur is often met with anxiety and worry – particularly for parents. But you may be surprised to learn that most people have a heart murmur. In fact, if you had a really good stethoscope and amplified it, you’d probably find a murmur in everyone. This will all make more sense after reading below. The bigger question is whether a heart murmur is normal or not.

Here, we walk through everything you need to know when it comes to heart murmurs. 

What Is a Heart Murmur?

People often misuse the term “murmur," making it sound like there is something wrong. In the same way they misuse the word “temperature” meaning they have a fever when, in fact, everybody has a temperature at any given time. Similarly, television weather reporters frequently misuse the term “weather” when they say “We’re having a bit of weather today.” We, of course, always have weather - if we did not, there wouldn't be a need for weather reporters. 

When it comes to the heart, everyone has blood flow and blood flow makes noise. A heart murmur simply means that a medical professional listened to your child's heart with a stethoscope and heard the sound of blood flowing.

However, the sound of blood flow isn't always evident for a few different reasons: 

  1. The patient may be obese making it more difficult to hear the sound of blood flow.
  2. There may be other noises drowning out the sound of blood flow such as crying, wheezing noises in the throat or coughing. Or, there may even be sounds in the exam room such as a ventilator that make it difficult to hear blood flow (a murmur). 

In these situations, it's not that the child doesn't have blood flow. It just means that it cannot be heard. In other words, a murmur isn't detected. 

There are also times when a murmur may be louder than usual. For example, when a child has a fever or when they're excited, anxious or exercising and have more blood flow. Just like if you have water in a pipe running faster, it makes a louder sound. 

How Do I Know If My Child Has a Heart Murmur?

Your child's healthcare provider will inform you if they detect a heart murmur. If there is concern it's abnormal, they will determine the appropriate course of action. 

How Common Are Heart Murmurs in Children?

Very common. Technically, healthcare providers should be able to hear a murmur in every quiet child. You shouldn’t be surprised if a pediatrician says they hear a murmur. In most cases, the murmur is likely normal. The important part is for your pediatrician or healthcare provider to determine whether this is something that is abnormal or requires further expertise.

How Serious Is a Heart Murmur in a Child?

The level of severity depends on whether the murmur is normal or not. If it’s abnormal, that means there is something wrong with the heart and a cardiologist will need to figure out the cause. If the murmur is abnormal, it could be benign or something more serious – you can’t tell by using the term “murmur” in and of itself. A cardiologist typically considers the murmur and other findings during an exam and puts it together to determine if any additional testing is needed. All the information from the exam and testing is then reviewed to decide what needs to be done next; if anything needs to be done at all.

Do Kids Grow Out of Heart Murmurs?

The simple answer is no. You always have blood flow so, technically, you should always hear a murmur. When you grow, you may not be able to hear the murmur but the blood flow is still there.

Is It Dangerous to Have a Heart Murmur?

A heart murmur isn't dangerous if it's a normal murmur. Even if it’s an abnormal heart murmur, it’s not necessarily dangerous. It all depends on the cardiac abnormality that’s causing the abnormal murmur. That’s something a cardiologist can tell you.

How Is a Heart Murmur Treated?

If it’s a normal heart murmur, your healthcare provider will just continue to provide reassurance that it's normal. 

If the murmur is abnormal, treatment would depend on the cause and a cardiologist will have to determine that on an individual basis.

Remember, though, you can develop heart abnormalities from diseases, such as Rheumatic fever, which can cause valve disease and results in abnormal blood flow and, therefore, abnormal murmurs later in life. 

Can Heart Murmurs Get Worse Over Time?

If it’s a normal murmur, it may be louder or softer at different points in time, but it shouldn't be of concern. While blood flow doesn’t get worse, a change in an abnormal murmur over time could mean there is a change in the underlying heart defect. That would need to be determined by a cardiologist who will then need to take a look at your child's overall medical history.  

Learn more about Heart Murmurs 

Learn More about Lurie Children's Heart Center