Health Health Article

HEALTH THEORIES AND THEIR PRACTICAL APPLICATION

Beliefs about the foundations of good health are inseparable from theories of disease. Primitive beliefs about good and evil spirits; the benevolent or malevolent intervention of fate, gods, or ancestors; disease as a punishment for sin (Murdock, 1980); theories such as those of Aristotle and Galen about the balance of bodily fluids (humors) and about the effects of miasmas or "bad air" survive in the names by which we know some common diseases, including influenza, malaria, cholera, and rheumatism. A preference for holiday resorts and convalescent hospitals at the seaside or in the mountains reflects a belief in the notion that some environments are inherently healthier than others—as, indeed, abundant evidence demonstrates.

Scientists can trace the evolution of medical science in the changing nomenclature of disease. Some modern diagnostic labels indicate a precise understanding of the causal mechanisms of disease—streptococal septicemia is, literally, the poisoning of the blood by streptococcus bacteria. Some that sound impressive, such as thrombocytopenic purpura (bruising associated with a deficiency of thrombocytes, or blood platelets) reveal partial knowledge: scientists know what causes the bleeding but not what causes the deficiency of platelets. Other disease names are deservedly vague—essential hypertension confesses out ignorance about what actually causes high blood pressure.

Modern medicine and public health embrace several theories that are confirmed by abundant empirical and experimental evidence, and medical professionals have an increasingly broad and deep understanding of the ways in which health of individuals and populations can be impaired, endangered, of permanently lost. Scientists know that many diseases are caused by invading pathogenic microorganisms, which are often communicable. Some diseases are due to a disruption or imbalance among endocrine glands that secrete hormones needed to ensure efficient bodily function, some are caused by dietary deficiency of essential vitamins or minerals, and others are caused by exposure to harmful chemicals or physical insults such as ionizing radiation or excessive noise. Some diseases are due to, or strongly associated with, emotional stress. There remains a residue of important, and sometimes common, diseases and causes of disability and premature death for which there is no known cause, although effective treatments have been developed for some of theses, often through trial and error or guesswork. High blood pressure is one such disease.

The activities of public health services aim to minimize the risk of serious departures from good health. The scope and methods of medical and public health practice demonstrate the depth and breadth of current understanding of the causes of disease, disability, and premature death, and also of the causes of good health.

Many who remain fit throughout a long lifetime attribute their good health (often incorrectly) to their behavior; whether it be to an ascetic or hedonistic way of life, to abstaining from (or indulging in) alcohol or tobacco, to vigorous exercise, or to leading a quiet, sedentary life. Some credit their parents or genetic heritage—certainly an important determinant of longevity—along with many environmental and behavioral factors. In fact, the causes of good health are as diverse and complex as the causes of disease.

Even literate, well-educated people sometimes have misguided views about what makes or keeps them healthy, often believing that regular daily exercise, regular bowel movements, or a specific dietary regime will alone suffice to preserve their good health. The Nobel laureate Linus Pauling believed that massive daily doses of Vitamin C preserved his health. Those who are less well educated and more gullible are easy prey to hucksters who purvey all manner of dubious nostrums to prolong life, enhance vitality or virility, promote fitness, and eliminate ailments ranging from halitosis and body odor to failing sexual potency and even cancer and heart disease.

Modern approaches to health education and health promotion make use of the Health Belief Model along with several other theoretical constructs to predict health-related behavior. These are based on assumptions derived from empirical studies of how people perceive their health and their understanding of what has to be done to preserve and protect their own health, or that of their children.