Extensive clinical and statistical studies have identified several factors that increase the risk for coronary heart disease (CHD). Some of them can be changed or treated, and some cannot.

According to the American Heart Association, these are as follow:

Risk Factors That Can't Be Changed

Age — Over 80 percent of people who die of CHD are age 65 or older. Men get heart attacks earlier than women.

Heredity — A family history of coronary heart disease in parents or siblings is a major risk factor. 

Risk Factors That Can Be Changed

Smoking — Smokers have double the risk of a heart attack than nonsmokers, since ingredients in tobacco can narrow blood vessels and produce blockages. Among those who have a heart attack, smokers are more likely to die that nonsmokers.

High cholesterol — The higher the blood cholesterol levels, the higher the risk of heart disease. According to Wikipedia, "In conditions with elevated concentrations of LDL particles, cholesterol promotes atheroma plaque deposits in the walls of arteries, a condition known as atherosclerosis, which is a major contributor to coronary heart disease and other forms of cardiovascular disease."

Hypertension — Persistent high blood pressure increases the heart's workload, possibly leading to strokes, heart attacks, heart failure, and arterial aneurysm.

Sedentary lifestyle — Lack of physical activity is a major risk factor for coronary heart disease. Regular, vigorous exercise prevents stiffening of the heart muscles and minimizes the workload of the circulatory system.

Obesity — People who have excess body fat are more likely to suffer from cardiovascular disease, congestive heart failure, enlarged hearts, arrhythmias, and strokes, even if they have no other risk factors. Excess weight increases the strain on the heart. Central obesity (excess weight carried predominantly around the waist) is an even greater risk factor.