Endocarditis (say "en-doh-kar-DY-tus") is an infection of the heart's valves or inner lining (endocardium) of the heart. It is most often caused by bacteria. It also can be caused by fungi. The bacteria or fungi get into the bloodstream. They settle and grow on the inside of the heart, usually on the heart valves. Bacteria or fungi can enter the bloodstream in many ways, such as injecting drugs and having some dental and medical procedures.

This infection can damage your heart. You need to treat it right away.

People who have a normal heart are not likely to get endocarditis. But some people are more likely to get it than others. This includes people who have a heart problem that affects normal blood flow, such as a heart valve problem, or people who inject drugs.

Endocarditis can be very serious. It may be more dangerous for people who:

• Have had certain heart problems since birth.
• Have had a heart valve replaced or repaired.
• Have had this kind of infection before.
• Have heart valve problems after a heart transplant.

Symptoms may appear quickly, within a few days of infection. In other cases, they may develop more slowly. The symptoms will get worse as the bacteria or fungi grow in your heart.

Symptoms may include:

• Flu-like symptoms such as fever, chills, night sweats, dizziness, and feeling tired. These are often the first symptoms.
• Shortness of breath.
• A cough.
• Muscle or joint pain.
• Blood under the fingernails or tiny purple and red spots under the skin.
• Weight loss.

Call your doctor right away if you have symptoms like these that don't go away, especially if you are at risk for endocarditis.

If endocarditis isn't treated right away, it can lead to more serious problems, such as:

• Heart failure.
• An abscess in the heart.
• Heart rhythm problems.
• Heart attack or stroke.
• Infections in other organs, such as the lungs, brain, or kidneys.

First, your doctor will ask about your medical history and your symptoms. The doctor will also do a physical exam to check for signs of the infection. These signs include a heart murmur, an enlarged spleen, and bleeding under the nails.

Your doctor may also do tests, such as:

• Blood cultures. These tests look for bacteria in your bloodstream.
• Echocardiogram. This is done to check your heart for problems such as infected areas or heart valve defects.
• An MRI test, a CT scan, or a PET (positron emission tomography) scan. These may be done as additional tests to check your heart for problems.
• Electrocardiogram (EKG or ECG). This test checks for heart rhythm problems.
• A chest X-ray. This is to see if your heart is enlarged or if you have signs of heart failure or lung problems.

Endocarditis is usually treated with antibiotics or antifungals. You will probably need several weeks of treatment. The antibiotics must be given long enough and at a strong enough dose to destroy all of the bacteria.

At first you will be treated in the hospital. This is so that antibiotics can be given through a vein (I.V.). After your fever is gone and you are stable, you may be able to continue I.V. antibiotics at home. A home health nurse can help you with this.

After you have been treated with I.V. antibiotics, your doctor may want you to take antibiotic pills. If so, take them exactly as prescribed until they are gone. If your symptoms come back, call your doctor right away. You probably will need more antibiotics if testing shows that the bacteria were not completely destroyed.

Some people who have endocarditis need surgery to repair or replace a heart valve. Or they may need surgery to take care of an infection, such as an abscess, or to prevent complications.

You may have follow-up visits for months or years to check the health of your heart.