Clinical studies, laboratory investigations and a number of surveys show certain personal characteristics and life-styles pointing to increased danger of heart attack (coronary heart disease). These danger signs are called "risk factors". The well established risk factors are high blood pressure, high blood cholesterol, cigarette smoking and diabetes mellitus. Other factors that may increase or affect the risk for heart attach are obesity, a sedentary life-style, an aggressive response to stress, and certain drugs.
In the past two decades, millions of Americans have learned about these risk factors and have tried to modify them favorable by seeking medical attention and by changing life-style. Many adults have stopped smoking. The medical control of high blood pressure has greatly improved. The average cholesterol level of the population has decreased continually over the last two decades, probably due to changes in dietary habits and increased exercise.
This attempt to modify risk factors almost certainly has contributed to the declining death rate from heart disease in the United States. During the 1960's, U.S. death rates from heart disease were still rising, but today the incidence from diseases of the cardiovascular system (including coronary heart disease) has fallen dramatically. Overall, heart-related problems have declined about 25 percent in the last decade. Some of this decrease undoubtedly is due to better medical care of heart attack victims, but it is likely that a sizable percentage is related to modification of risk factors.
The entire population has become more aware of the seriousness of heart disease and coronary heart problems. CPR training is offered in schools, places of business, and church and community functions, and everyone seems to recognize that prevention of coronary heart disease is a partnership between the public and the medical community.
There are a number of factors implicated in coronary heart disease. Some of these may raise coronary risk by accentuating the major risk factors already discussed. Others may act in ways not understood. Still others may be linked mistakenly to coronary risk.
Obesity predisposes individuals to coronary heart disease. Some of the reasons for this are known, but others are not. The major causes of obesity in Americans are excessive intake of calories and inadequate exercise. When caloric intake is excessive, some of the excess frequently is saturated fat, which further raises the blood cholesterol. Thus, obesity contributes to higher coronary risk in a variety of ways.
Most of the major risk factors are silent. They must be sought actively, and much of the responsibility for their detection lies with each of us as individuals. Regular checkups are particularly necessary if there is a family history of heart disease, high blood pressure, high cholesterol levels or diabetes.