Preventive medicine seeks to reduce the incidence of disease by modifying theenvironmental or behavioral factors that caused the illness in the first place.
Originally, preventive medicine was largely concerned with understanding andpreventing infectious disease. Today, however, its scope has widened. The aimof preventive medicine is to preserve good health; to prevent disease, injury, and disability; and to facilitate early diagnosis and treatment of illness.
Preventive medicine has become a very diverse and challenging medical specialty. Preventive medicine physicians are trained in the sciences of epidemiology, biostatistics, environmental and occupational health services, administration, as well as clinical prevention. They are uniquely qualified to work withboth individuals and the community to promote health and prevent disease, initiating programs in infectious disease prevention and control, sexually transmitted diseases, and in chronic disease prevention. They use scientific methods to identify health hazards in the workplace and work to prevent occupational illness and injury.
Preventive services offered to infants and children, adolescents, pregnant women, and adults have three components. The first step is a thorough health screening. This is done to identify disease or discover risk factors for certain diseases. The screening includes taking an extensive medical history and assessing the lifestyle pattern for risk factors. A physical examination follows the screening, which may include laboratory tests.
The next step in preventive medicine involves counseling. If the person's lifestyle has too many risk factors--such as smoking, over use of alcoholor other drugs, sex with multiple partners, unprotected sex--the physician explains the relationship between the risk factors and disease. The preventivemedicine specialist will then either assist the patient or will direct the patient toward somebody who will help him to acquire the knowledge, motivation, and skills needed to maintain healthful behavior.
Immunization against infectious diseases and chemoprophylaxis (medication toprevent future diseases) form the third step of preventive medicine.
Clinical prevention strategies have proved to be extremely successful. Certain diseases, which were once common and often debilitating, have declined following the introduction of preventive services. Infectious diseases such as poliomyelitis, which once occurred in regular epidemic waves, have become rareas a result of childhood immunization. Similar trends have been seen with diphtheria, pertussis, and other common childhood infections. As a result of newborn screening and treatment, children with metabolic disorders such as phenylketonuria can now lead normal lives. (If the disease were left unidentifiedand untreated, they would have suffered irreversible mental retardation.)
Similarly, implementation of the screening programs such as the PAP test hasled to dramatic reductions in the incidence of cervical cancer and the mortality associated with it. Early detection and treatment of hypertension has significantly reduced the incidence of death from stroke.
Although immunizations and screening tests remain important preventive services, the most challenging role for preventive medicine specialists lies in altering the lifestyle patterns of patients long before clinical disease develops. Currently, some of the leading causes of death in the United States are heart attacks, cancer, cerebrovascular disease, chronic obstructive pulmonary disease, accidents, and human immunodeficiency virus infections. Almost all ofthese can be prevented (or the risks minimized) by changing lifestyle patterns. Smoking contributes to one out of every five deaths in the USA. It is responsible for a large number of deaths from cancer, coronary artery disease, cerebrovascular disease, and pulmonary diseases. Failure to use safety belts and drunk driving are the major contributors to motor vehicle fatalities. Physical inactivity and dietary factors contribute to heart disease, diabetes, cancer, osteoporosis, and other diseases. High-risk sexual practices increase the risk of sexually transmitted diseases and AIDS. Most of these deaths are potentially preventable by changes in personal health practices.
Environmental strategies for health protection, such as providing safe waterfor drinking, fluoridation, lead abatement, regulations on public smoking, seat-belt laws, and safer highways, require the commitment of the entire community. Once these changes are made, they can have a far-reaching impact.