Endocarditis is inflammation of your heart's inner lining, called the endocardium. It's usually caused by bacteria. When the inflammation is caused by infection, the infection is called infective endocarditis. Endocarditis is uncommon in people with healthy hearts.

The symptoms of endocarditis aren’t always severe, and they may develop slowly over time. In the early stages of endocarditis, the symptoms are similar to many other illnesses. This is why many cases go undiagnosed.

Many of the symptoms are similar to cases of the flu or other infections, such as pneumonia. However, some people experience severe symptoms that appear suddenly. These symptoms may be due to inflammation or the associated damage it causes.

The main cause of endocarditis is an overgrowth of bacteria. Although these bacteria normally live on the inside or outside surfaces of your body, you might bring them inside to your bloodstream by eating or drinking.

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