Coronary heart disease is
caused by a narrowing of the coronary arteries that feed the heart. Like any muscle, the heart needs a constant supply of oxygen and
nutrients, which are carried to it by the blood in the coronary
When the coronary arteries
become narrowed or clogged by cholesterol and fat deposits--a process
called atherosclerosis--and cannot supply enough blood to the heart,
the result is coronary heart disease (CHD).
Atherosclerosis 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 coronary heart
disease. 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 heart disease. Being 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 coronary heart disease.