Medical is the branch of science concerned with human health and disease. Medicine is the practice of using drugs or surgery to treat illness. Medical practitioners include physicians, physician assistants, nurse practitioners, midwives, dentists, and other healthcare professionals. Medicine is a vast field with many sub-fields and specialties, including biomedical engineering, genetic counseling, clinical psychology, endocrinology, pharmacology, radiology, and surgery. The term medicine can also refer to the underlying scientific disciplines, such as biology and chemistry, that support medical research and practice.
A medical encounter is a doctor-patient interaction, which typically takes place in a clinical setting such as a hospital or private clinic. It is an opportunity for the patient to describe their symptoms and medical history to a doctor, and to receive a diagnosis and treatment plan. The visit is documented in the patient’s medical record. The medical encounter is a cornerstone of the patient-doctor relationship and is central to health promotion and disease prevention.
Primary care is the first point of contact for most people with a health problem. Physicians, physician assistants, and nurse practitioners provide the bulk of primary care services in most countries, treating common illnesses and promoting good health. In addition to office visits and outpatient care, they may provide community health education, home health aide service, and school-based health services.
Secondary care is provided by medical specialists in their offices or clinics and at local community hospitals for patients referred to them by primary care providers. These services include consultation, diagnostic evaluations and treatments, surgical procedures, follow-up examinations, and other specialized services.
The earliest known medical practices date from prehistoric times and included the use of plants (herbalism), animal parts, or mineral substances for medicinal purposes. Spiritual systems such as animism, spiritualism, and shamanism also played a role in early healing. Modern scientific biomedical research began with Edward Jenner’s introduction of the smallpox vaccine in 1761 and Robert Koch’s discovery of bacteria as the cause of disease in the 1880s.
There are two major categories of medicine: internal medicine and surgery. Internal medicine includes many sub-specialties such as gastroenterology, hematology, and oncology. Radiology is the study of diseases based on the detection and imaging of bodily tissues. Biochemistry is the study of the chemical reactions taking place in living organisms. Molecular biology studies the structure and function of genes and proteins. Biomechanics applies the principles of physics and mechanical engineering to biological systems.
Physiology is the study of normal body processes and how to maintain them. The medical subspecialties of ob/gyn and urology focus on the reproductive and urinary tracts, respectively. Most medical specialties require a minimum of three years postgraduate training, although this varies around the world. The core of medical education is a foundation in the basic sciences of biology, chemistry, physics, and mathematics, along with the humanities and social sciences. The majority of medical students also undergo specialized training in their chosen field. Often this involves a lengthy period in residency.