A heart attack occurs when blood flow to the heart is blocked, usually due to a buildup of fat, cholesterol and other substances in the arteries. The main symptoms for men are chest pain, pain radiating to the jaw or arm, nausea and shortness of breath, while the main symptoms for women can include fatigue, weakness and lightheadedness without chest pain. If symptoms occur, it is important not to drive oneself to the hospital and instead to call 911, chew baby aspirin and sit or lay down. Prevention involves smoking cessation, monitoring cholesterol levels, exercise, weight control and diet control.