Irritation and swelling of the inner lining of the heart's chambers and valves. Usually caused by infection.

Endocarditis usually happens when germs get in the bloodstream and stick to damaged areas of the heart. People with damaged or artificial heart valves or other heart conditions are most at risk.

Common symptoms include chest pain when breathing, shortness of breath, sore muscles and joints, fever, and chills. Some people have night sweats.

Quick treatment is needed to prevent long-term heart valve damage. Treatment includes medicines called antibiotics to kill germs. Some people need surgery to fix or replace damaged heart valves.