context: When your heart pumps blood, it's supposed to follow along a specific path in one direction. But sometimes, it goes the wrong way. â Mitral valve regurgitationâ is the name for one of those times when your blood isn't going where it should. With this condition, some of it leaks backward instead of flowing out to the rest of your body. You may feel tired and out of breath if you have it. You may also have higher blood pressure and a buildup of fluid in your lungs. A doctor can figure out whether you have a mild case and might not even need treatment, or a more serious situation that will need medication or surgery. Before you understand the details of how blood can flow the wrong way in one part of your heart, you need to know how things should work. The heart has four chambers: the left and right atrium on top and, below them, the left and right ventricles. As your heart beats, it draws blood from the body into the right atrium. This chamber sends it down to the right ventricle. From there, your blood is pumped to the lungs to pick up oxygen. When that oxygen-rich blood goes back to the heart, the left atrium takes it in and passes it down to the left ventricle. That chamber contracts, or squeezes, to send it to your body. You have a passageway between the left atrium and the left ventricle. That is the mitral valve. The mitral valve is supposed to be a one-way passage. It has flaps that should close behind the surge of blood it sends to the left ventricle. But sometimes the valve doesn't seal properly. That allows blood to flow backward through it, returning to the left atrium. When this happens, you have mitral valve regurgitation. You might hear a doctor sometimes call it âmitral valve insufficiency.â The most common reason this happens is because the mitral valve is damaged. This can be either from birth or because of a heart attack, which can weaken the tissue around it. You might hear a doctor say a valve is âprolapsedâ if it doesn't close up the way it should. Other possible causes: A buildup of calcium can keep it from working as it should Rheumatic fever, which can develop as a result of strep throat, can damage your mitral valve A type of bacterial infection called âinfective endocarditis,â which attacks the lining of your heart's chambers and valves, might also cause it Severe regurgitation can cause blood clots, gel-like clumps that can create serious problems if they get to the lungs or brain. The condition can also cause fluid to build up in the lungs, straining the right side of the heart. If you have regurgitation, less blood is going to your body. Your heart works harder to make up for the shortfall. If this goes on long enough, your heart could enlarge, making it harder to pump blood and raising the risk of heart failure. It also can lead to an irregular, or uneven, heartbeat or a stroke. Many people with only mild regurgitation won't notice any symptoms. But if the condition worsens, you might have: Heart palpitations, which happen when your heart skips a beat. They produce feelings in your chest that can range from fluttering to pounding. They may be more likely to happen when you're lying on your left side. Coughing Fatigue Shortness of breath Rapid breathing Chest pain Doctors usually find a problem with your heart valve by sound. If blood is leaking back into your left atrium, it will produce a murmur or a whooshing sound. Your doctor can hear that through a stethoscope (you probably see your family doctor wearing one around her neck). A common follow-up test is called an echocardiogram. This uses sound waves to make a picture of your beating heart, similar to the ultrasound tests given to pregnant women. Your doctor might also want to get a CT or MRI scan of your chest to help figure out what's going on. These are just two more ways to get a visual picture of your insides. If you have a really mild case, you might need no treatments at all. Your doctor will still want to keep a watchful eye on you with regular checkups. Medications can't actually fix a valve problem, but they can target other things that make regurgitation worse. Drugs called diuretics (or âwater pillsâ) can lessen fluid buildups. Blood thinners can help prevent clots. You can take something if you have high blood pressure, which makes regurgitation worse. In tougher cases, you might need an operation. Sometimes, a surgeon can fix your valve. If it has to be replaced, she can implant either a man-made device or one taken from a cow, a pig, or a person who died and donated the organ. People who have had valve surgery are often asked to take antibiotics before they have dental work or other surgery to prevent endocarditis, or inflammation of the heart valves or inner lining of the heart. You should ask your doctor whether you'll need to take them.