Endocarditis is an infection of the inner lining of the heart, known as the endocardium. It usually occurs when bacteria or other germs enter the bloodstream and attach to damaged areas of the heart. This condition can affect heart valves and lead to serious complications if not treated promptly. Symptoms of endocarditis may include fever, chills, fatigue, and heart murmurs. Risk factors include having a history of heart valve problems, previous endocarditis, or certain medical conditions. Treatment typically involves antibiotics and, in severe cases, surgery to repair or replace damaged heart valves.