Can A Heart Murmur Get Worse? | When To Worry

Yes, murmurs can change or get louder when blood flow shifts or a valve problem progresses, so new symptoms call for a medical check.

A heart murmur is an extra sound heard during a heartbeat. It’s not a diagnosis by itself. It’s a clue that blood is moving in a way that makes audible turbulence. Many murmurs are innocent and never turn into heart disease. Others come from valve narrowing, valve leak, a hole between chambers, or infection.

If you already have a murmur, “getting worse” can mean three different things: the sound changes on exam, new symptoms show up, or a heart test shows a change. The sections below break down each one, plus what you can do between visits.

What “worse” can mean in real life

Most people don’t mean the same thing when they say a murmur got worse. Here are the common versions.

• Louder on exam: Your clinician hears it more strongly than before.
• Different pattern: It lasts longer, shifts in timing, or sounds harsher.
• New body signals: Breathlessness, fainting, swelling, chest pressure, or a fast irregular heartbeat.
• Changed echo findings: An echocardiogram shows more valve leak, more narrowing, or new strain on the heart.

Those changes don’t all carry the same risk. A murmur heard during a fever can fade once you’re well. A murmur tied to valve disease can change slowly and still need action at the right time.

Heart murmur getting worse: common reasons

Murmurs get louder when blood moves faster or when the route gets tighter or leakier. The cause matters, since some triggers are temporary and others can progress.

Fast-flow triggers that can come and go

When your body runs hot or low on fluid, the heart often beats faster and pumps harder. That can make a harmless flow sound easier to hear. Fever, dehydration, anemia, pregnancy, and an overactive thyroid can all do this. Once the trigger settles, the sound may soften again.

Valve and structure changes that may progress

Abnormal murmurs often come from valve disease. Two broad patterns show up:

• Narrowing (stenosis): A valve opening gets tighter, so blood has to squeeze through.
• Leak (regurgitation): A valve doesn’t seal well, so blood slips backward with each beat.

Valve problems can stay stable for years, then shift as the valve stiffens, calcifies, or stretches. Other structural causes include a small hole between chambers, thickened heart muscle, or changes after heart surgery.

Can A Heart Murmur Get Worse? What changes mean

Clinicians use your symptoms plus what they hear to decide whether testing is needed. The American Heart Association notes that innocent murmurs usually need no treatment, while abnormal murmurs can signal heart problems that may need tests or follow-up. American Heart Association heart murmur overview explains the innocent-versus-abnormal split and why extra tests may be used.

Mayo Clinic also notes that innocent murmurs often have no symptoms, while murmurs tied to disease can come with signs such as shortness of breath, chest pain, fainting, swelling, or bluish lips in some cases. Mayo Clinic heart murmur symptoms and causes lists symptom patterns clinicians watch for.

So the answer is “yes,” but it’s not a straight line from louder sound to serious disease. The safest approach is to treat a changing murmur as a prompt to check for a trigger and, when needed, confirm what’s going on with an echocardiogram.

Signs that deserve a faster appointment

You can’t grade the murmur yourself, yet you can notice changes in how your body feels. These are common signals clinicians take seriously:

• Breathlessness with activity you used to handle
• Breathlessness at rest or waking at night gasping
• Chest pressure or pain with exertion
• Fainting or near-fainting
• New ankle swelling, belly swelling, or rapid weight gain over days
• Fast or irregular heartbeat that’s new for you

For infants and children, urgent signs can include poor feeding, poor growth, sweating with feeds, rapid breathing, or blue color around lips.

How clinicians check whether the cause is changing

Most workups start with your story and a careful exam. Then testing is chosen to match the risk.

The exam details that steer the next step

Clinicians listen for when the murmur occurs (during the squeeze or the relaxation phase), where it is loudest, and whether it travels toward the neck or back. They also check blood pressure, pulse pattern, swelling, and lung sounds. Your symptom history matters just as much as the sound.

Tests that often settle the question

• Echocardiogram: Shows valve shape, leak or narrowing severity, chamber size, and pumping strength.
• Electrocardiogram (ECG): Checks rhythm and strain patterns.
• Chest imaging: Can show heart size and fluid in the lungs when symptoms point that way.
• Blood tests: Can check anemia, thyroid levels, infection markers, and kidney function.
• Exercise testing: Links symptoms to exertion when the story and echo don’t match.

When valve disease is found, follow-up usually follows guideline-based timing for repeat echoes and referrals. The ACC valvular heart disease guideline hub is a public entry point to the ACC/AHA materials used in that care.

If valve disease is found, follow-up often includes repeat echoes on a schedule based on severity and symptoms.

Table of changes, likely causes, and next steps

This table groups common “it feels worse” scenarios into practical next moves. It won’t diagnose you, yet it can help you decide how quickly to be seen.

Change you notice	What it can point to	Next step
Murmur first noticed during fever	Fast-flow state making a benign sound easier to hear	Recheck after recovery
Murmur louder at a routine visit, no symptoms	Flow trigger, anemia, pregnancy, thyroid shift, or valve change	Ask if an echo or labs are due
New breathlessness with stairs	Valve narrowing/leak, anemia, rhythm issue, lung disease	Book a prompt visit
Chest pressure with exertion	Aortic stenosis, coronary disease, blood pressure strain	Same-week evaluation
Fainting or near-fainting	Valve obstruction, arrhythmia, blood pressure drop	Urgent assessment
New swelling plus weight gain over days	Fluid build-up from heart strain or other illness	Prompt visit; track weight daily
Fast, irregular heartbeat that’s new	Atrial fibrillation or another arrhythmia	Same-day check if you feel unwell
Fever with chills in a person with valve disease	Possible valve infection	Urgent care

When to seek urgent or emergency care

Get urgent or emergency care if you have any of these:

• Chest pain at rest, or chest pain that lasts more than a few minutes
• Fainting, severe dizziness, or sudden weakness
• Breathlessness at rest or pink frothy sputum
• Blue-gray lips or face
• Stroke signs like face droop, arm weakness, or speech trouble

What treatment can look like

Treatment targets the cause behind the sound. Some causes are reversible, and some need long-term follow-up.

When the murmur is driven by a reversible trigger

If anemia is the driver, treating the anemia can reduce the murmur. If thyroid overactivity is the driver, getting thyroid levels under control can soften the sound. If dehydration is the driver, rehydration can change what’s heard.

When valve disease is the driver

Valve disease care often has two parts: symptom relief and timing the right intervention.

• Blood pressure control: Can reduce strain on the heart and ease symptoms in some valve problems.
• Diuretics: Can reduce swelling and breathlessness from fluid retention.
• Rhythm treatment: Can help when atrial fibrillation or other rhythm issues appear.

If a valve becomes severely narrowed or leaky, repair or replacement may be advised. Some aortic valve problems can be treated with transcatheter aortic valve replacement (TAVR), while other situations call for surgery. Timing is based on symptoms, echo findings, and how the heart is coping.

What you can do between visits

A few habits can make follow-up clearer and reduce surprises.

Keep a simple symptom log

Write down breathlessness, chest pressure, palpitations, swelling, and lightheadedness when they happen. Note what you were doing, how long it lasted, and whether rest helped. A simple timeline often speeds up decision-making at appointments.

Track weight if swelling is part of your pattern

If you’ve had swelling before, weigh yourself daily for a week when symptoms flare. A steady rise over days can point to fluid build-up.

Bring your baseline to the visit

Tell your clinician what “normal” looks like for you: your usual walking distance, how many stairs you can climb, and whether you sleep flat or need extra pillows.

Table of symptom patterns and how fast to act

Use this as a quick sorter while you’re lining up care.

Pattern	How fast to act	Why it matters
Stable murmur, no symptoms, activity level unchanged	Routine follow-up	Many murmurs stay harmless or stable
New breathlessness with routine activity over 1–3 weeks	Prompt appointment	Can signal valve change or anemia
New palpitations that recur	Prompt appointment	Rhythm issues can change symptoms and clot risk
Swelling plus weight gain over days	Prompt appointment	Fluid retention can build quickly
Chest pressure with exertion that repeats	Same-week evaluation	Can line up with valve obstruction or coronary disease
Fainting, chest pain at rest, or breathlessness at rest	Urgent or emergency care	Can signal a high-risk change

Takeaway

Yes, a heart murmur can get worse, yet the meaning depends on the cause. If the sound changes or symptoms appear, get checked and ask whether an echocardiogram is due. Staying alert to breathlessness, chest pressure, fainting, swelling, and new rhythm changes is the safest way to catch valve problems early.