The circulatory, or cardiovascular (kard-ee-oh-VAS-kyew-ler), system consists of the heart and blood vessels that pump and circulate blood throughout the body. The major forms of cardiovascular disease are atherosclerosis (ath-uh-roe-skluh-ROE-sis), high blood pressure, stroke, and congestive heart failure. The most common of these, atherosclerosis, occurs when arteries become clogged with deposits of fat, cholesterol (kuh-LES-tuh-rawl), or other material, restricting the flow of blood. This is a major contributor to heart attacks and strokes. High blood pressure, or hypertension (hi-per-TEN-shun), occurs when too much pressure is asserted against the walls of the arteries, making it difficult for the heart to push blood forward. This greatly weakens the heart and arteries, and contributes to a number of serious illnesses. Strokes occur when the blood supply to the brain is cut off and are particularly serious because they can cause permanent damage to the brain or even death. Congestive heart failure occurs when the heart cannot maintain its regular pumping rate and force. This allows fluids to back up in the lungs, which can greatly interfere with breathing. You can protect yourself against cardiovascular disease by monitoring your blood pressure, engaging in regular exercise, eating a proper 'low-cholesterol' diet, and not smoking. To learn more about the causes, methods of prevention, and treatments of circulatory problems, please consult a physician.