Blood To The Heart example essay topic

Introduction Some 7 million Americans suffer from coronary heart disease (CHD), the most common form of heart disease. This type of heart disease is caused by a narrowing of the coronary arteries that feed the heart. CHD is the number one killer of both men and women in the U.S. Each year, more than 500,000 Americans die of heart attacks caused by CHD. Many of these deaths could be prevented because CHD is related to certain aspects of lifestyle.

Risk factors for CHD include high blood pressure, high blood cholesterol, smoking, obesity, and physical inactivity -- all of which can be controlled. Although medical treatments for heart disease have come a long way, controlling risk factors remains the key to preventing illness and death from CHD. Like any muscle, the heart needs a constant supply of oxygen and nutrients that are carried to it by the blood in the coronary arteries. When the coronary arteries become narrowed or clogged and cannot supply enough blood to the heart, the result is CHD. If not enough oxygen-carrying blood reaches the heart, the heart may respond with pain called angina.

The pain is usually felt in the chest or sometimes in the left arm and shoulder. (However, the same inadequate blood supply may cause no symptoms, a condition called silent angina.) When the blood supply is cut off completely, the result is a heart attack. The part of the heart that does not receive oxygen begins to die, and some of the heart muscle may be permanently damaged. What Causes CHD CHD is caused by a thickening of the inside walls of the coronary arteries. This thickening, called arteriosclerosis, narrows the space through which blood can flow, decreasing and sometimes completely cutting off the supply of oxygen and nutrients to the heart. Arteriosclerosis usually occurs when a person has high levels of cholesterol, a fat-like substance, in the blood.

Cholesterol and fat, circulating in the blood, build up on the walls of the arteries. The buildup narrows the arteries and can slow or block the flow of blood. When the level of cholesterol in the blood is high, there is a greater chance that it will be deposited onto the artery walls. This process begins in most people during childhood and the teenage years, and worsens, as they get older.

In addition to high blood cholesterol, high blood pressure and smoking also contribute to CHD. On the average, each of these doubles your chance of developing heart disease. Therefore, a person who has all three risk factors is eight times more likely to develop heart disease than someone who has none. Obesity and physical inactivity are other factors that can lead to CHD. Overweight increases the likelihood of developing high blood cholesterol and high blood pressure, and physical inactivity increases the risk of heart attack. Regular exercise, good nutrition, and smoking cessation are key to controlling the risk factors for CHD.