Bacterial endocarditis is an infection of the inner lining of the heart, usually affecting the heart valves. It occurs when bacteria enter the bloodstream and attach to damaged areas of the heart. This can happen due to various reasons, such as dental procedures, intravenous drug use, or existing heart conditions. Symptoms may include fever, fatigue, and heart murmurs. If left untreated, bacterial endocarditis can lead to serious complications, including heart failure or stroke. Diagnosis typically involves blood tests and imaging studies. Treatment usually requires antibiotics and, in some cases, surgery to repair or replace damaged heart valves.