A heart attack occurs when part of the heart muscle is damaged or dies because of a lack of blood flow and oxygen to the area. Atherosclerosis, the leading cause of heart attacks, occurs when plaque builds up along the artery walls. Over time, the plaque hardens and may block the arteries. If you experience symptoms of a heart attack, call 911. Common Heart Attack Symptoms Chest discomfort and lightheadedness, sweating, nausea or shortness of breath Chest tightness or chest pain Pain or discomfort that spreads to the jaw, neck, shoulders, arms or back Less Common Heart Attack Symptoms Anxiety