Yes, mitral valve regurgitation is a form of heart disease. Specifically, it falls under valvular heart disease, a category that covers any condition where one or more of the heart’s four valves doesn’t work properly. The American College of Cardiology and American Heart Association classify it alongside other valve disorders in their clinical guidelines, and it carries its own formal staging system ranging from at-risk (Stage A) through severe symptomatic disease (Stage D).
That said, being told you have mitral regurgitation doesn’t automatically mean you’re in danger. Mild cases are extremely common and may never cause problems. What matters is severity, whether it’s progressing, and how your heart is adapting to it.
What Happens Inside the Heart
The mitral valve sits between the two left chambers of your heart. Every time the lower chamber (the left ventricle) squeezes to push blood out to your body, the mitral valve is supposed to snap shut so blood only flows forward. In mitral regurgitation, the valve doesn’t close completely, and some blood leaks backward into the upper chamber.
When the leak is small, your heart compensates easily and you likely won’t notice anything. When it’s moderate or severe, the backward flow means your heart has to work harder to pump enough blood forward. Over time, the extra volume stretches the heart chambers. The left side of the heart gradually enlarges, the valve ring itself widens (which can make the leak even worse), and eventually the heart muscle weakens. This is the progression from a valve problem into heart failure, and it’s why mitral regurgitation is taken seriously even when symptoms haven’t appeared yet.
Two Types With Different Causes
Doctors distinguish between primary and secondary mitral regurgitation because the underlying problem, and the treatment approach, differ significantly.
Primary mitral regurgitation means something is wrong with the valve itself. The most common cause is degenerative disease, where the valve tissue becomes floppy or thickened over time. A prolapsed valve, torn valve cords, or calcium buildup on the valve leaflets all fall into this category. In degenerative disease, the ring around the valve can enlarge in ways that aren’t fully explained by the leak alone, suggesting the tissue surrounding the valve is inherently weakened.
Secondary (or functional) mitral regurgitation means the valve structure is essentially normal, but the heart around it has changed shape. Heart attacks, coronary artery disease, or a dilated heart muscle can pull the valve leaflets apart so they no longer meet in the middle. In these cases, the regurgitation is a consequence of another heart problem rather than the root cause.
Symptoms to Recognize
Many people with mild or even moderate mitral regurgitation have no symptoms for years. When the condition does produce symptoms, they typically include fatigue, shortness of breath (especially when lying flat), heart palpitations, and swollen feet or ankles. Because the heart isn’t pumping blood forward efficiently, the body and brain don’t get the oxygen supply they need, which is why tiredness is often the earliest complaint.
Shortness of breath tends to worsen gradually, making it easy to dismiss as aging or being out of shape. The irregular heartbeat many people notice is often atrial fibrillation, a rhythm disorder that develops as the upper heart chamber stretches from the extra blood volume backing up into it.
How Severity Is Measured
An echocardiogram (an ultrasound of the heart) is the primary tool for grading mitral regurgitation. Doctors measure several things: how much blood is leaking backward per heartbeat, the size of the opening in the valve where the leak occurs, and what percentage of the heart’s output is going the wrong direction.
The ACC/AHA guidelines use a four-stage system. Stage A means you’re at risk but don’t yet have a leak. Stage B is mild to moderate regurgitation with a heart that’s still compensating well. Stage C is severe regurgitation where the heart is starting to show strain, even if you feel fine. Stage D is severe regurgitation with clear symptoms. This staging matters because treatment decisions hinge not just on how bad the leak is, but on how your heart and lungs are responding to it.
When the Leak Gets Dangerous
Left untreated, severe mitral regurgitation carries a poor prognosis. A large study of over 600,000 people who had echocardiograms found that five-year mortality was 54.6% for moderate cases and 67.5% for severe cases, compared to 19.2% for those with no meaningful regurgitation. After adjusting for age, sex, and valve condition, people with severe mitral regurgitation had a 2.36 times higher risk of death than those without it.
Despite those numbers, intervention rates remain surprisingly low. A French national study found that only 8% of people with severe mitral regurgitation had a valve procedure within one year of diagnosis. A Mayo Clinic study found just 15% of a cohort with moderate-to-severe disease underwent intervention. Conservative management in these patients consistently led to higher rates of heart failure, atrial fibrillation, and death over the following decade. By contrast, surgical repair performed early in the disease markedly improved all of those outcomes.
Treatment Options
For mild mitral regurgitation, the typical approach is monitoring with periodic echocardiograms to track whether the leak is worsening or the heart is enlarging. No surgery or medication is needed at this stage.
When regurgitation becomes severe, or when the heart begins to dilate even without symptoms, intervention becomes the priority. Current guidelines favor lower thresholds for surgery than in the past, because procedures have become safer and more durable. Surgeons strongly prefer valve repair over valve replacement when possible. Repair preserves your own valve tissue, maintains better heart function long-term, and avoids the complications that come with an artificial valve, including the risk of blood clots and eventual valve failure.
For people who are too high-risk for open-heart surgery, a less invasive option exists. A catheter-based procedure clips the valve leaflets together to reduce the leak. This approach is performed through a vein rather than through the chest, and it’s specifically recommended for patients with severe symptoms who aren’t good candidates for traditional surgery.
When secondary mitral regurgitation is caused by heart failure, treating the underlying heart failure with medications and other therapies is the first step. The catheter-based clip procedure can help a specific subset of these patients who remain severely symptomatic despite optimal heart failure treatment.
Living With Mitral Regurgitation
If you’ve been told you have mitral regurgitation, the most important thing to know is where you fall on the severity spectrum. A trace or mild leak found incidentally on an echocardiogram is common, particularly as people age, and it rarely changes your life or your life expectancy. Moderate and severe cases are a different story and warrant active follow-up, because the transition from a compensated heart to a failing one can happen gradually and without obvious warning signs.
Regular echocardiograms let your doctor track the size of the leak, the dimensions of your heart chambers, and how well your heart muscle is contracting. These measurements, not symptoms alone, drive decisions about timing of surgery. One of the clearest findings in the research is that early intervention, before the heart muscle weakens irreversibly, produces dramatically better outcomes than waiting until symptoms become severe.