A heart attack (myocardial infarction) occurs when the heart’s supply of blood is occluded transiently or permanently. Lack of oxygen to the heart muscle causes tissue damage with enzymes leaking into the blood stream that allow doctors to detect it as raised creatinine kinase, myoglobin and troponins. A heart attack may be fatal, especially if you did not receive medical attention and treatment to deal with the blockage soon. A heart attack manifests as severe central chest pain, which may also radiate to the left arm, shoulder or jaw. Severe shortness of breath, sweating, nausea and faint are common symptoms. If you are a woman, however, your experience of heart attack may differ. Rather than acute chest pain you may have difficulty breathing, be very, very tired and have pain in your shoulder, jaw, or upper back pain.