A heart attack occurs when a coronary artery becomes blocked, preventing blood and oxygen from reaching the heart muscle. Over time, fatty deposits can build up in the arteries and eventually rupture, forming a clot that causes a complete blockage. Common symptoms of a heart attack include chest pain or discomfort that may spread to the arms, shoulders, neck or jaw. Treatment focuses on quickly restoring blood flow through clot-busting drugs, angioplasty, stents or bypass surgery. Lifestyle changes and cardiac rehabilitation are important for recovery.