African-Americans are also more likely to have high blood pressure than whites. The incidence of high blood pressure isn't directly related to a person's sex. However, doctors usually keep a close watch on a woman's blood pressure during pregnancy or if she's taking oral contraceptives. Some women who've never had high blood pressure develop it during pregnancy. Similarly, a woman taking oral contraceptives is more likely to develop high blood pressure if she's overweight, has had high blood pressure during pregnancy, has a family history of high blood pressure or has mild kidney disease.
Heart attacks result from blood vessel disease in the heart.
Such an event is sometimes called a coronary thrombosis or coronary occlusion. If the blood supply is cut off drastically or for a long time, muscle cells suffer irreversible injury and die. Sometimes a coronary artery temporarily contracts or goes into spasm. When this happens the artery narrows and blood flow to part of the heart muscle decreases or even stops. What causes a spasm is unclear, but it can occur in normal blood vessels as well as vessels partially blocked by atherosclerosis.