Medicine
From Encyclopædia
The practice of medicine is devoted to the maintenance of good health. This involves the detection and prevention of disease, the curing of those disorders for which treatment exists, and, in all
cases, the amelioration of
pain and minimizing of disabilities. Modern medicine has also assumed the task of improving
public health by promoting hygiene and advancing standards for nutrition and the environment. Medical
science in the 20th century has experienced a rapid
growth in its informational and technological resources. This
growth has been accompanied by increasingly complex patterns of health-care delivery. The importance of health care in modern society is reflected in the fact that about 10 percent of the gross national product of technologically advanced societies is devoted to serving the health needs of their citizens. Society, in turn, has made increasing demands for greater access to health care and for greater accountability from the healing professions.Scarcely a century ago, health care was primarily the task of the family or neighborhood physician, who diagnosed and treated patients and prepared medications with no assistance other than unskilled help. In contrast, the modern physician has become only one--although an essential component--in an enterprise that
numbers among the largest enterprises in developed countries, both in terms of
money and in terms of the
numbers of persons employed.
hospitals, which are among the largest employers, form the largest single component of health-care costs. Another large component is
education, which in addition to medical schools and schools of nursing includes technical schools required for discrete fields of training (laboratory and
radiology technicians, among others) and educational programs for health care administration (see MEDICINE,
education IN).Modern medicine also requires ongoing research in various fields of
science as well as the continuing development of clinical procedures and technologies. Such research and development is an international endeavor, running into tens of billions of dollars. Much of it is done in universities, medical schools, and governmental institutions, but the
pharmaceutical industry is also a major contributor. International in nature, the industry is dominated by a few giant U. S. and Swiss firms. In the
United States alone, annual
sales of
drugs and other chemicals exceed $30 billion, and a vast distribution system is needed to bring the products to pharmacies and
hospital dispensaries.THE BRANCHES OF MEDICINEUntil the 20th century, most physicians were general practitioners. Of those who specialized, or confined their practice to a narrower field, the majority were surgeons. Specialists in other fields were found mainly on the faculties of medical schools. With the
growth of
science in the 20th century, however, medicine began to harvest results such as the ability to produce standardized
drugs, to analyze the constituents of blood and body tissues, and to examine patients by means of
X rays and
electrocardiographs. This, in turn, stimulated the development of specialization.In the
United States and Canada, medicine is currently divided into 23 distinct areas, each with its own rule-making and certifying body. The largest divisions, such as internal medicine,
pediatrics, and
surgery, are further divided into subspecialties that have additional requirements for training and certification. In the following description, these 23 divisions are grouped under the more general categories of nonsurgical, surgical, and
hospital-based specialties, with family practice as a separate field. For a description of the fields of nursing, see NURSING.Nonsurgical SpecialitiesThe nonsurgical specialties that involve direct patient care include internal medicine,
pediatrics, allergy and IMMUNOLOGY, DERMATOLOGY, preventive medicine, and
psychiatry and NEUROLOGY.Practitioners of internal medicine, or internists, are concerned with the diagnosis and treatment of adults with diseases of the internal
organs. Those called ge?eral internists are primary-care physicians, in that they have a direct relationship with patients on a long-term basis and refer them to other specialists only for specific problems. Many internists, however, specialize in a specific area of the body. This had led to the formation of nine subspecialties of internal medicine, as follows:Cardiology is the care of patients with diseases of the heart and blood vessels. Endocrinology and
metabolism is the care of patients who have problems related to glands of the body, and gastroenterology is the study of diseases of the gastrointestinal tract; it also deals with diseases of the
liver and pancreas. HEMATOLOGY treats patients with diseases of the blood
cells, bone marrow, and lymph nodes; hematologists also operate
blood banks and manage patients with blood-clotting disorders. Infectious disease specialists are consulted chiefly in the treatment of severe or exotic infections, the selection and use of antibiotics, and the management of complications resulting from their use. Specialists in nephrology are experts in the diagnosis and treatment of
kidney diseases, also managing blood-dialysis centers for patients who lack functioning
kidneys. Oncology involves the treatment of cancer patients with chemotherapeutic
agents; oncologists frequently act in the capacity of general internists for such patients. Pulmonary disease is concerned with disease of the lung and air passages. Finally, rheumatology specialists treat patients with joint diseases and joint-related systemic diseases such as rheumatoid
arthritis and lupus erythematosus.
pediatrics is constituted much like internal medicine, but it deals instead with infants and children. The new field of adolescent medicine, however, has extended these traditional age limits. Recognized pediatric subspecialties include pediatric cardiology, hematology/onocology, endocrinology, and nephrology. These subspecialties differ from their adult counterparts, because infants and children have distinctive diseases and disease patterns. One subspecialty unique to
pediatrics is neonatal-perinatal medicine, dedicated to the management of premature infants and ill newborns. Specialists in this field also aid the obstetrician in caring for a child at risk before birth.Allergy and immunology, besides dealing with hypersensitivity disorders such as asthma and food allergies, also treats immune-related problems such as patients with
organ transplants and patients incapable of manufacturing the various components of the
immune system. A practitioner in this field has already completed training as an internist or pediatrician.Dermatology is the study of diseases of the
skin. Since the majority of human diseases have at least some effect on the
skin, this field of medicine intersects with many other specialties. The dermatologist must understand the systemic diseases likely to be responsible for the
skin rash, just as the internist or pediatrician examines the
skin as a first clue to underlying disease. Occupational dermatology is the study of
skin manifestations resulting from some environmental factor in work areas.Preventive medicine studies involve improving the level of health in a community. Most work in the area of preventive medicine and
public health is done under the
aegis of a government,
university, or institute, and many such specialists are found as public-health officers. Those interested in such a career customarily attend a School of
public health and receive a master's degree, the MPH. Training encompasses a thorough grounding
In STATISTICs,
epidemiology, microbiology, and immunology. Holders of an MPH are often not physicians, but physicians form a necessary element in public-health organizations. Two subspecialties exist: occupational medicine, devoted to detecting and measuring adverse effects of the workplace; and aerospace medicine (see
SPACE MEDICINE).
psychiatry and neurology is divided into two obvious subspecialties.
psychiatry is concerned with those brain functions expressed as behavior, mood? and
intelligence, whereas neurology is concerned with organic diseases of the
Central nervous system, including the brain. In general, psychiatrists treat patients with nonorganic diseases of the brain, whereas neurologists treat those with organic diseases. Organic diseases are those in which the immediate cause can be observed directly or under a microscope or can be identified chemically, while nonorganic diseases are those in which functional disturbances exist but no anatomical or chemical basis is identifiable. Psychiatrists also spend much of their professional time treating emotional responses to chronic disease.Surgical SpecialitiesSURGERY and the surgical specialities include general, colon and rectal, orthopedic, plastic, and thoracic
surgery, otolaryngology, OPHTHALMOLOGY, and urology. OBSTETRICS and
gynecology exhibit important elements both of
surgery and of general medicine.General
surgery deals with those conditions which require operative
interventions not falling within the areas of the related disciplines listed above. If required, however, the general surgeon can deal with most surgical problems, having mastered the techniques basic to all the fields. The anatomical areas with which the general surgeon is most concerned are the abdomen and its contents; many surgeons specialize further, such as
breast surgeons and thyroid surgeons. The subspecialties of general
surgery are pediatric
surgery, which deals with surgical problems of children, and
hand surgery.
