A heart murmur is, as the name suggests, a sound that occurs during a heartbeat, caused by rapid, turbulent blood flow through the heart. Characterised as a whooshing or swishing sound, these heart murmurs can be heard through a stethoscope. But what really causes these sounds, and what can people do about them? Are they innocent or harmless, or abnormal and dangerous? To answer the same, the OnlyMyHealth team spoke to Dr Prateek Chaudhary, Senior Consultant - Interventional Cardiology, Asian Hospital, Faridabad, and here's what he shared.
What Is A Heart Murmur?
Dr Chaudhary described a heart murmur as a sound made by turbulent blood flow within the heart or major blood vessels near the heart. "It is heard through a stethoscope and may resemble a whooshing or swishing noise," he notes, adding that murmurs are not diseases in themselves but may indicate either a normal or abnormal condition of the heart.
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Doctors typically detect murmurs during a routine physical examination by listening to different areas of the chest. The timing (systolic or diastolic), pitch, and location of the murmur help doctors understand its significance. According to Johns Hopkins Medicine, murmurs are graded on a scale of 1-6, based on how loud they are. One means a very faint murmur. Six means a murmur that's very loud.
According to StatPearls Publishing, cardiac auscultation, or listening to the heart with a stethoscope, is a simple but powerful way for doctors to spot potential heart problems early. When done well, it can help detect heart murmurs with impressive accuracy (70% sensitivity and 98% specificity).
While some murmurs are harmless (especially in children or during pregnancy), others may signal more serious issues like valve problems, heart defects, or anaemia.
Abnormal Vs Innocent Heart Murmurs: What Are The Differences?
According to Dr Chaudhary, innocent murmurs are usually soft, short, and heard during systole, i.e., when the heart contracts. They are not associated with any other symptoms and often vary with body position or activity. On the other hand, abnormal murmurs may be louder, longer, occur during diastole, i.e., when the heart relaxes, or have additional sounds such as a “thrill” (a vibration felt on the chest).
If a murmur is accompanied by symptoms such as chest pain, fatigue, shortness of breath, or poor growth in children, it is more likely to be abnormal and requires further evaluation.
The good news is that in most cases, an innocent murmur does not become serious or indicate an underlying heart problem. Innocent murmurs are especially common in children and often disappear with age as the heart and chest wall develop.
However, a murmur that changes in character or is associated with new symptoms should be re-evaluated. “It is rare, but possible, that what was once thought to be an innocent murmur could later be found to be due to a mild structural issue that has progressed or become more noticeable over time,” notes Dr Chaudhary.
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Tests To Evaluate The Cause Of Heart Murmur
If a murmur is suspected to be abnormal or if the patient shows signs of heart problems, doctors may order additional tests. The most common test is an echocardiogram, which uses ultrasound waves to create images of the heart and assess its structure and function.
Other tests may include an Electrocardiogram (ECG) to measure the heart’s electrical activity or a chest X-ray to check the size and shape of the heart. In some cases, more advanced imaging or a referral to a cardiologist may be needed.
Heart Murmur In Children
Heart murmurs may be common in healthy children, indicating innocent murmurs, which are usually not concerning. However, in some cases, a child may be born with a heart defect that causes a murmur.
Dr Chaudhary advises parents to consult a doctor if a heart murmur is detected in their child, especially if it is accompanied by symptoms such as poor weight gain, frequent respiratory infections, fatigue during feeding, bluish skin or lips, or shortness of breath.
However, it’s important to know that most murmurs in children are innocent and harmless.
“Paediatricians are skilled at identifying features of murmurs that may indicate a need for further evaluation. If the murmur is deemed suspicious, the doctor may refer the child to a paediatric cardiologist for an echocardiogram and further assessment,” he adds.
Conclusion
Discovering a heart murmur, whether in yourself or your child, can naturally cause worry, but it’s not always something to fear. Many murmurs are completely harmless, especially in kids, and often go away on their own as the body grows. What matters most is recognising when a murmur might need a closer look, especially if it’s paired with symptoms like breathlessness, tiredness, or chest discomfort. With routine check-ups and the right tests, doctors can easily tell whether a murmur is innocent or something more serious. When in doubt, don’t hesitate to seek medical advice.