Many definitions of health exist. Most definitions consider health as an outcome—the result of actions to produce it, such as good nutrition, immunization to prevent disease, or medical treatment to cure disease. The American Heritage Dictionary defines health as fixed and measurable—"the overall condition of an organism at a given time." However, health also may be vie…
Preventing disease involves a wide range of interrelated programs, actions, and activities. Some prevention measures are sweeping global policy initiatives, such as national and state government actions to reduce health risks by limiting air pollution and other toxic exposures or standards to assure the safety of food and water supplies. Others are focused efforts of public health professionals an…
The practice of medicine often is considered to be both science and art because identifying the underlying causes of disease and establishing a diagnosis require that health care practitioners use a combination of scientific method, intuition, and interpersonal (communication and human relations) skills. Diagnosis relies on the powers of observation; listening and communication skills; analytical …
Genetics, which is the branch of biology that studies heredity, concerns the biochemical instructions that convey information from generation to generation. In order to appreciate the role of genetics in health and illness, it is important to understand the interaction of genes, chromosomes, and genomes and to learn how deoxyribonucleic acid (DNA) functions as the information molecule of living or…
The Centers for Disease Control and Prevention (CDC) define chronic diseases as prolonged illnesses that do not resolve spontaneously and are rarely cured completely. According to the CDC, chronic illnesses such as cardiovascular disease, cancer, respiratory disease, cerebrovascular disease, and diabetes account for 70% of all deaths in the United States and almost half of the years of potential l…
Degenerative diseases are noninfectious disorders characterized by progressive disability. Patients often can live for years with their diseases. Although they may not die from degenerative diseases, patients' symptoms usually grow more disabling and they often succumb to complications of their disorders. …
Infectious (contagious) diseases are caused by microorganisms—viruses, bacteria, parasites, or fungi—transmitted from one person to another through casual contact, such as influenza; through bodily fluids, such as HIV (human immunodeficiency virus); or via contaminated food, air, or water supplies. Infectious diseases also may spread by vectors of disease such as insects or arthropod…
Mental health may be measured in terms of an individual's abilities to think and communicate clearly, learn and grow emotionally, deal productively and realistically with change and stress, and form and maintain fulfilling relationships with others. Mental health is a principal component of wellness—self-esteem, resilience, and the ability to cope with adversity influence how people …
The National Center for Complementary and Alternative Medicine (NCCAM; formerly the Office of Alternative Medicine, established in 1992) is an institute of the National Institutes of Health (NIH). The center was created because consumers of complementary and alternative medicine (CAM) and health care practitioners wanted to know whether available alternative medical options were safe and effective…