Diseases of the Circulatory System

Unfortunately, diseases of the circulatory system are all too common. Cardiovascular diseases—especially heart disease and stroke—are among the leading causes of death and disability in the United States. High blood pressure and a condition known as atherosclerosis (ath-ur-oh-skluh-ROH-sis) are two of the main causes of cardiovascular disease. Atherosclerosis is a condition in which fatty deposits called plaque build up on the inner walls of the arteries.

High Blood Pressure If blood pressure is too high, medical problems may result. High blood pressure, or hypertension, forces the heart to work harder, which may weaken or damage the heart muscle and blood vessels. People with high blood pressure are more likely to develop coronary heart disease and to suffer from other diseases of the circulatory system. Hypertension increases the risk of heart attack and stroke.

Consequences of Atherosclerosis Atherosclerosis is particularly dangerous in the coronary arteries, which bring oxygen and nutrients to the heart muscle itself. If one of these arteries becomes blocked, part of the heart muscle may begin to die from a lack of oxygen. If enough heart muscle is damaged, a condition known as a heart attack occurs.

The symptoms of a heart attack include nausea, shortness of breath, and severe, crushing chest pain. People who show these symptoms need immediate medical attention. New drugs are available that can increase blood flow enough to save the heart, but they must be given in the early stages of a heart attack to save the heart muscle and prevent death.

Blood clots that can form as a result of atherosclerosis may break free and get stuck in one of the blood vessels leading to a part of the brain. This condition is known as a stroke. Brain cells served by the particular blood vessel gradually die from a lack of oxygen, and brain function in that region may be lost. Depending on what part of the brain they affect, strokes may cause paralysis, loss of the ability to speak, and death.

Circulatory System Health Like other diseases, cardiovascular diseases are easier to prevent than to cure. Some of the ways of avoiding cardiovascular disease include getting regular exercise, eating a balanced diet, and avoiding smoking. Exercise makes your heart muscle stronger and more efficient. It also helps control your weight, reduces body fat, and reduces stress.

A diet low in saturated fat and cholesterol can reduce your risk of developing heart disease as well. High levels of fat and cholesterol in the blood increase the likelihood that it will be deposited onto the artery walls. This process begins in childhood and worsens as you get older. For this reason, you should limit your intake of foods with saturated fat. A low-fat diet will also help control your weight. Being overweight enlarges the circulatory system, causing the heart to pump harder to force blood through it. The cardiovascular system is also damaged by smoking. You will learn more about the effects of smoking later in this chapter. A timeline of some advances in cardiovascular medicine is shown at right.

Cardiovascular Advances