A heart murmur is an extra sound a doctor hears through the stethoscope, and it is one of the most common findings at a checkup. A sizable share of people have one, from children to pregnant people to older adults. How common a murmur is and what it means change sharply with age and life stage, so the same sound can be routine in a child and worth checking in a 75-year-old.
How Common Heart Murmurs Are In Adults
When family doctors listened to more than 2,000 ordinary adults over 40, they heard a murmur in 23%, nearly 1 in 4.1The Cardiovascular. Heart murmurs in adults: assessment and when to refer Almost all were systolic murmurs, heard while the heart squeezes. Murmurs between beats were rare, found in just 9 people.2PubMed Central. Heart murmurs in the general population: diagnostic value and prevalence from the Tromsø Study Rates climb with age: 38% of people 70 or older had one, versus 16% of younger adults.3The Cardiovascular. Heart murmurs in adults: assessment and when to refer Women had murmurs more often than men, 28% versus 18%.4The Cardiovascular. Heart murmurs in adults: assessment and when to refer Serious valve disease, though, was more common in men, so a murmur in a woman is less likely to signal it.5The Cardiovascular. Heart murmurs in adults: assessment and when to refer Murmurs also turned up more often in people with high blood pressure, diabetes, a past heart attack, or heart failure.6PubMed Central. Heart murmurs in the general population: diagnostic value and prevalence from the Tromsø Study
“Heard a murmur” means the doctor noticed a whooshing or swishing sound between the normal heart sounds. It is a sound, not a diagnosis. Many people never knew they had one until a routine exam.
Murmurs are so common because a murmur is the sound of turbulent blood flow, and it becomes audible only once the turbulence passes a certain strength.7PubMed. Turbulent blood flow in humans: its primary role in the production of ejection murmurs Anything that makes blood move faster or rougher can create one, even in a normal heart. A murmur caused by fast flow rather than a heart defect is called an innocent, or harmless, murmur.
Age changes the picture because valves stiffen and thicken over the years. The higher rates after 70 partly reflect real valve wear, so a new murmur in an older adult deserves more attention.
A murmur on the exam is a clue, not a verdict. The same sound can come from a perfectly normal heart or from a damaged valve, so the stethoscope finding alone can’t say which. Doctors weigh it together with your age, symptoms, blood pressure, and the rest of the exam before deciding whether more testing is needed. A soft, brief murmur heard only during the squeeze is more often harmless. A loud one, one heard between beats, or one that spreads to the neck is more likely to prompt an ultrasound, though these are clues that raise or lower concern rather than a dependable sorting rule. Because a murmur can change with how fast your heart is beating, a doctor may hear it at one visit and not the next, and that alone isn’t alarming.
Murmurs In Children And Newborns
More than two-thirds of school-age children may have a harmless murmur at some point.8University Health. Are Innocent Heart Murmurs in Kids a Cause for Concern? In one study of 5- to 14-year-olds, 41% had a common harmless “vibratory” murmur at a single exam.9PubMed. The vibratory innocent heart murmur in schoolchildren: a case-control Doppler echocardiographic study The louder versions fade with age, from 21% at ages 5 to 6 down to 8% at ages 13 to 14.10PubMed. The vibratory innocent heart murmur in schoolchildren: a case-control Doppler echocardiographic study So a harmless childhood murmur often quietens or disappears as a child grows.
This common murmur, sometimes called a Still’s murmur, is thought to come from normal blood flow making the tissues near the heart’s exit valve vibrate. Children also have thin chest walls and fast heart rates, so heart sounds carry more clearly to the stethoscope than in adults. Because the sound reflects normal anatomy, it does not mean a hole or a damaged valve. Parents are often surprised, since the child feels fine and has never had a problem. That is typical: the murmur is usually found by chance at a routine visit or when the child has a fever.
To call a murmur innocent, a pediatrician checks several things. The sound is soft and musical. It changes with position or breathing. The child is growing well and has no symptoms, and the exam turns up nothing else abnormal.
The murmur can even change within one visit. A harmless one often sounds louder when the child lies flat and softer or gone when they sit or stand, because posture changes how much blood fills the heart. Fever, excitement, or crying speeds the heart and makes a murmur easier to hear, which is why one may be noticed only during an illness, a point that fits the harmless pattern but doesn’t settle it alone. If it fades when the child is calm and well, that reassures the doctor it is the harmless kind.
Newborns are different. Murmurs are found in only about 1% to 3% of newborns at routine checks.11PubMed Central. But in those babies, roughly 4 to 5 in 10 turned out to have a heart defect.12PubMed Central. Prevalence and clinical significance of heart murmurs detected in routine neonatal examination The most common was a small hole between the lower chambers, which your baby’s report may call a ventricular septal defect.13PubMed Central. Congenital heart disease diagnosed with echocardiogram in newborns with asymptomatic cardiac murmurs: a systematic review Still, only about 3% needed surgery or a procedure before going home.14PubMed Central. Congenital heart disease diagnosed with echocardiogram in newborns with asymptomatic cardiac murmurs: a systematic review
If your newborn has a murmur, a heart ultrasound is commonly ordered. Many small holes close on their own, and a murmur heard in the first days may simply be normal transition flow as the baby’s circulation adjusts to life outside the womb.
Murmurs During Pregnancy And Other Harmless Causes
About 90% of pregnant people develop a murmur.15University of Utah Health. Should You Worry About a Heart Murmur? Blood volume rises a lot during pregnancy, which speeds flow through the heart.16University of Utah Health. Should You Worry About a Heart Murmur? The heart pumps more with each beat and beats faster, which makes blood flow noisy enough to hear even though the valves work normally. These murmurs are typically soft, heard during the squeeze, and often show up in the second trimester while blood volume is climbing. A pregnancy murmur deserves a second look if it comes with breathlessness out of proportion to pregnancy, chest pain or fainting, or if you had a known heart condition before pregnancy.
Low red blood cells (anemia) and an overactive thyroid can cause harmless murmurs too.17Mayo Clinic. Heart murmurs – Symptoms and causes Treating the underlying cause, such as anemia, can make the murmur go away. Fever and exertion do something similar by speeding the heart, so a doctor may recheck once you are well.
Afterward, blood volume returns toward normal over the following weeks, the extra flow settles, and the murmur usually fades. If it is still there after recovery, that doesn’t mean something is wrong, but a doctor may suggest an ultrasound to check the valves directly. A harmless murmur during pregnancy generally doesn’t change plans for labor or delivery.
When A Murmur Points To Valve Disease
In the same general-population adults, 19% had at least mild narrowing or moderate leaking of a key valve on ultrasound.18The Cardiovascular. Heart murmurs in adults: assessment and when to refer Among more than 1,200 people referred to a clinic for a murmur, 156 had significant heart disease and 23 needed surgery over 5 years.19PubMed. The not so innocent heart murmur: a 5-year experience People over 65 were more likely to have structural heart disease, 16% versus 11%.20PubMed. The not so innocent heart murmur: a 5-year experience The most common problems were aortic stenosis, a narrowed aortic valve, and mitral regurgitation, a leaky mitral valve.21PubMed. The not so innocent heart murmur: a 5-year experience Many of these findings are mild and only need monitoring.
A narrowed aortic valve is common in older people and may show up only as a murmur.22PubMed. The patient with a systolic murmur: severe aortic stenosis may be missed during cardiovascular examination It makes a harsh sound during the squeeze, often loudest near the upper right of the chest and sometimes carrying toward the neck. Many people feel fine for years because the heart compensates. But once symptoms start, it can cause sudden death with little warning.23PubMed. The patient with a systolic murmur: severe aortic stenosis may be missed during cardiovascular examination An older adult with a new murmur should have it checked, not ignored. An ultrasound measures how tight the valve is and how hard the heart is working, which is how doctors grade it as mild, moderate, or severe.
A leaky mitral valve from wear affects at least 24 million people worldwide.24PubMed Central. Degenerative mitral regurgitation The valve lets some blood flow backward into the heart’s upper chamber with each beat, creating a murmur. Many leaks are mild and cause no symptoms, so the finding often means regular monitoring rather than treatment. When the leak is severe, the heart can enlarge and tire, symptoms such as breathlessness may appear, and repair or replacement is considered.
Some signs make a murmur urgent: chest pain or tightness on exertion, fainting or near-fainting, breathlessness, or swollen ankles. So does a new or changing murmur with fever.
Why Many Heart Problems Make No Murmur
Among adults with significant valve disease, only about 1 in 3 had a murmur a doctor could hear.25Heart. Heart murmurs in the general population: diagnostic value and prevalence from the Tromsø Study Everyone with a significantly narrowed aortic valve did have one.26Heart. Heart murmurs in the general population: diagnostic value and prevalence from the Tromsø Study A leaky valve was audible in 10% to 40% of mild cases but 86% to 100% of severe ones.27PubMed. Prevalence of regurgitant murmurs in patients with valvular regurgitation detected by Doppler echocardiography In people with heart failure, severe mitral leaks were missed by the stethoscope about 3 times in 4.28PubMed. High prevalence of clinically silent severe mitral regurgitation in patients with heart failure: role for echocardiography And when people 65 and older were screened by ultrasound, 6.4% had moderate or severe valve disease nobody knew about.29PubMed Central. Large-scale community echocardiographic screening reveals a major burden of undiagnosed valvular heart disease in older people: the OxVALVE Population Cohort Study
A stethoscope can miss valve disease because a murmur needs turbulent flow strong enough to carry through the chest wall. A leak or narrowing that is mild, or that moves little blood, may make no audible sound. Body size, lung sounds, a noisy room, and a fast heart rate can all make a faint murmur harder to hear.
A tight aortic valve forces blood through a small opening, which reliably creates loud turbulence. That is why a stethoscope exam is more dependable for this problem than for leaks, and why a clearly normal exam makes a significantly narrowed aortic valve less likely, though not impossible in every situation.
An echocardiogram, a heart ultrasound, shows the valves and flow directly. It is the test doctors use to tell a harmless murmur from disease. You lie down while a technician spreads gel on your chest and moves a probe over it. It is painless, uses no radiation, and takes about 30 to 60 minutes. The results describe each valve.
No murmur does not rule out heart disease. If you have breathlessness or fainting, tell your doctor even if nothing was heard, and ask whether an ultrasound makes sense.
What To Do After Being Told You Have A Murmur
Start by asking the doctor whether the murmur sounds innocent and why. If the doctor can’t tell, it is reasonable to ask whether an ultrasound would settle the question. For older adults or anyone with symptoms, ask about a heart ultrasound.
People facing barriers like transport, insurance, or rural distance are less likely to get valve disease diagnosed.30Journal of the Heart Valve Society. Turning Awareness Into Action: Information Technology-Based Solutions to Address Care Gaps and Disparities in Valvular Heart Disease If follow-up is hard to arrange, say so, so the referral doesn’t stall.
Useful questions to bring: Is it innocent, or does it need testing? What grade is it? When should it be rechecked?
The grade is a loudness score, often from 1 to 6, with low numbers faint and high ones loud enough to feel through the chest. Loudness is one clue but not a precise measure of severity, since a quiet murmur can come from a serious valve and a loud one from a harmless cause. Knowing the grade lets a later doctor compare and see whether the murmur has changed.
With a known harmless murmur, there are usually no activity limits. Mention it to new doctors, and report new symptoms promptly.