Heart attacks happen when there is a blockage preventing the heart from getting the blood it needs. This blockage means that the heart isn't able to get oxygen, which in turn can cause the death of the heart muscle if the blockage isn't quickly corrected.
The most common reason that people have heart attacks today is coronary heart disease. People with coronary heart disease have considerable plaque buildup inside the walls of the arteries. This plaque buildup eventually hardens and causes the arteries to become progressively narrower. Due to the narrow space, sufficient quantities of blood can't get to the heart any longer and the heart muscle starts to die due to lack of oxygen. Another common reason for heart attacks is the development of blood clots, which in turn create a blockage in a coronary artery. This blockage prevents the delivery of oxygen-rich blood and means that the heart muscle starts to die rapidly.
Men who are over age 45 and women who are over age 55 have an increased risk of heart attack. Family history can play a role in heart attacks. Anyone who has a family history of heart disease has an elevated risk of heart attack, even if they don't have heart disease themselves. There are also a number of heart attack risk factors that are entirely controllable. These include obesity, type II diabetes, an inactive lifestyle, high cholesterol, high blood pressure, and cigarette smoking.
If a heart attack is suspected but not yet confirmed, some measures can be taken until an EKG confirms it. This can include taking aspirin, taking nitroglycerin, or oxygen therapy. After the heart attack has been confirmed, more aggressive treatment can start, including angioplasty, medications to eliminate blood clots, or other treatments as indicated.