The mitral valve is one of the four valves in your heart. Heart valves have flaps that open and close. The flaps make sure that blood flows in the right direction through your heart and to the rest of your body. When your heart beats, the flaps open to let blood through. Between heartbeats, they close to stop the blood from flowing backwards.

The mitral valve opens to let blood flow from your heart's upper left chamber to the lower left chamber. When the lower left chamber contracts (squeezes) to pump blood to your body, the mitral valve closes tightly to keep any blood from flowing backwards.

Mitral valve prolapse (MVP) happens when the flaps of the mitral valve become floppy and don't close tightly. In some cases, blood may leak backwards through the valve to the chamber it came from. This is called backflow, or regurgitation. When there is a lot of mitral valve backflow, the heart can't push enough blood out to the body.

But most people who have MVP don't have any backflow. In fact, MVP doesn't cause any health problems for most people who have it.

Anyone can have MVP. Most people who have it were born with it. MVP tends to run in families, but researchers don't know the exact cause.

You may be more likely to develop MVP if you:

• Are older. The risk of MVP increases as aging affects the valve.
• Had rheumatic fever, a disease that can develop after a strep throat infection and cause damage to the heart valves.
• Were born with a connective tissue disorder, such as Marfan syndrome or Ehlers-Danlos syndrome.
• Have Graves' disease, a type of thyroid condition.
• Have scoliosis (a side-to-side curve of the spine) or other problems with the bones of your body.
• Have some types of muscular dystrophy.

Mitral valve prolapse with backflow is most common in men and people who have high blood pressure.

Most people who have MVP don't have any symptoms. But if it does cause symptoms, they may include:

• Heart palpitations (feeling that your heart is fluttering, skipping beats, or beating too hard or too fast)
• Shortness of breath (feeling like you can't get enough air)
• A cough
• Fatigue, dizziness, or anxiety
• Migraines
• Chest pain

In rare cases, MVP can cause other problems. They're most often caused by backflow. They can include:

• Arrhythmia, a problem with the rate or rhythm of your heartbeat
• Endocarditis, an infection in the lining of the heart and heart valves
• Heart failure

Health care providers often find MVP during routine health check-ups. If you have MVP, your provider may hear a clicking sound when listening to your heart with a stethoscope. If blood flows backwards through the valve, your heart may also make a whooshing sound called a heart murmur.

You may also need certain heart tests. The most useful test is an echocardiogram, or echo. This is a type of ultrasound that uses sound waves to make a moving picture of your heart.

Most people don't need any treatment for MVP. If you have symptoms with little or no backflow, you may only need medicine to relieve your discomfort.

If the amount of backflow is significant, you may need treatment to prevent other heart problems from developing. Treatments may include:

• Medicines to help your heart work better.
• Heart surgery to repair or replace a very abnormal mitral valve with backflow. The goal of surgery is to improve your symptoms and reduce your risk of developing heart failure.

When possible, valve repair is generally preferred over replacement. That's because repairs are less likely to weaken the heart muscle, and they're less likely to cause heart infection.

You can't prevent mitral valve prolapse. But if you have mitral valve prolapse, you can help prevent the rare but serious problems it can cause by:

• Brushing and flossing your teeth regularly. That helps keep bacteria out of your bloodstream, which further reduces the rare risk of a heart infection.
• Asking your provider if you need to take antibiotics before dental work or surgery to lower your risk of heart infection. This mostly applies to people who have had valve repair or replacement surgery.
• Getting regular check-ups and taking any medicines that your provider may have prescribed.
• Making heart-healthy habits part of your life to prevent heart disease.

NIH: National Heart, Lung, and Blood Institute