A physician, medical practitioner, doctor of medicine, or medical doctor practices medicine, and is concerned with maintaining or restoring human health through the study, diagnosis, and treatment of disease and injury. This is accomplished through a detailed knowledge of anatomy, physiology, diseases and treatment — the science of medicine — and its applied practice — the art or craft of medicine.

Physician as any medical practitioner

Especially in North America, the title physician is now widely used in the broad sense, and applies to any legally qualified and licensed practitioner of medicine. In the United States and Canada, the term physician is used to describe those holding the degrees of Doctor of Medicine (MD), Doctor of Osteopathic Medicine (DO). It is also used to describe the holders of medical degrees from other countries when practicing in North America (in the UK and other Commonwealth countries, such degrees are typically MB BS, MB BChir etc which are equivalent to the US MD degree). The American Medical Association, established in 1847, uses physician in this broad sense to describe all its members.

Physician as specialist (or subspecialist) in internal medicine

Physician is still widely used in its older, more narrow sense, especially outside North America. In this usage, a physician is a specialist in internal medicine or one of its many sub-specialties (especially as opposed to a specialist in surgery). This traditional meaning of physician conveys a sense of expertise in treatment by drugs or medications, rather than by the procedures of surgeons.

Henry VIII granted a charter to the London Royal College of Physicians in 1518. It wasn’t until 1540 that he granted the Company of Barber/Surgeons (ancestor of the Royal College of Surgeons) its separate charter. In the same year, the English monarch established the Regius Professorship of Physic at the University of Cambridge. Newer universities would probably describe such an academic as a professor of internal medicine. Hence, in the 16th century, physic meant roughly what internal medicine does now. These days, a specialist physician in this older, narrower sense would probably be described in the United States as an internist.

The older, more narrow usage of physician as an internist is common in the United Kingdom and other Commonwealth countries (such as Australia, Bangladesh, India, New Zealand, Pakistan, South Africa, Sri Lanka, Zimbabwe), as well as in places as diverse as Brazil, Hong Kong, Indonesia, Japan, Ireland, and Taiwan. In such places, the more general English terms doctor or medical practitioner are prevalent, describing any practitioner of medicine (whom an American would likely call a physician, in the newer, broad sense). In Commonwealth countries, specialist pediatricians and geriatricians are also described as specialist physicians who have sub-specialized by age of patient rather than by organ system.

Physician and Surgeon

Around the world, the combined term “Physician and Surgeon” is a venerable way to describe either a general practitioner, or else any medical practitioner irrespective of specialty. This usage still shows the older, narrower meaning of physician and preserves the old difference between a physician, as a practitioner of physic, and a surgeon. The term may be used by state medical boards in the United States of America, and by equivalent bodies in provinces of Canada, to describe any medical practitioner.

Other Designations

Osteopaths are recognized as physicians (in the broad sense) in 48 countries, particularly in the USA. Internationally, there are variations in the D.O. degree. Osteopathic education includes teaching manipulative medicine. In a few jurisdictions, physician may also refer to holders of the Doctor of Naturopathic Medicine (ND or NMD). However, it should be noted that only those with medical degrees from schools listed in the WHO Directory of Medical Schools or the FAIMER International Medical Education Directory are permitted to apply for medical licensure. In the US, podiatrists have a Doctor of Podiatric Medicine degree (DPM) and are referred to as podiatric physicians and typically fall under the Department of Surgery in most hospitals.

Nurse practitioners (NPs) are not described as physicians; the American College of Nurse Practitioners do not describe themselves this way. They are classified as advance practice registered nurses/clinicians. Nurse practitioners may perform work similar to that of physicians, especially within the realm of primary care, but utilize both advanced clinical and nursing models. The scope of practice for a Nurse Practitioner in the United States is defined by individual state boards of registration in nursing, as opposed to state boards of registration in medicine. Physician Assistants are classified as advance practice clinicians, and are regulated by state boards of registration in medicine.

Social role

Physicians are traditionally considered to be members of a learned profession, because of the extensive training requirements, and also because of the occupation’s special ethical and legal duties. Physicians are often members, or fellows of professional organizations such as the Royal College of Physicians in the United Kingdom.
prescription symbol

The practice of medicine has ancient associations with religion and magic; see article on History of medicine. Medical practitioners are also often considered to be socially conservative. One curious example of these traditions is this symbol for prescriptions or treatment, still in common use by modern physicians. It is probably derived from the following hieroglyph, the Eye of Horus.

Doctors using it are perhaps thus invoking (unwittingly for the most part) an ancient Egyptian god—Horus— in a spell many thousands of years old.

Physicians commonly enjoy high social status, often combined with expectations of a high and stable income and job security. However, medical practitioners often work long and inflexible hours, with shifts at unsociable times, and may earn less than other professionals whose education is of comparable length.

Some commentators have argued that physicians have duties to serve as role models for the general public in matters of health, for example by not smoking cigarettes.

Education and training

All medical practitioners

In all developed countries, entry-level medical education programs are tertiary-level courses, undertaken at a medical school attached to a university. Depending on jurisdiction and university, entry may follow directly from secondary school or require pre-requisite undergraduate education. The former commonly take five or six years to complete. Programs that require previous undergraduate education (typically a three or four year degree, often in Science) are usually four or five years in length. Hence, gaining a basic medical degree may typically take from five to eight years, depending on jurisdiction and university.

Following completion of entry-level training, newly graduated medical practitioners are often required to undertake a period of supervised practice before full registration is granted, typically one or two years. This may be referred to as “internship” or “conditional registration”. Some jurisdictions (like the United States) require residencies for practice.

Medical practitioners hold a medical degree specific to the university from which they graduated. This degree qualifies the medical practitioner to become licensed or registered under the laws of that particular country, and sometimes of several countries, subject to requirements for internship or conditional registration.

Specialists in internal medicine

After graduation, medical practitioners often undertake further training in a particular field, to become a medical specialist. In North America, this is often referred to as residency training; in Commonwealth countries, such trainees are often called registrars.

This further training typically takes from three to six years, but can be longer depending on specialty and jurisdiction. Primary care is increasingly recognized as a specialty, and residency programmes in this field are becoming common. A medical practitioner who completes specialist training in internal medicine (or in one of its sub-specialties) is an internist, or a physician in the older, narrower sense.

In some jurisdictions, specialty training is begun immediately following completion of entry-level training, or even before. In other jurisdictions, junior medical doctors must undertake generalist (un-streamed) training for one or more years before commencing specialization. Hence, depending on jurisdiction, a specialist physician (internist) often does not achieve recognition as a specialist until twelve or more years after commencing basic medical training — five to eight years at university to obtain a basic medical qualification, and up to another nine years to become a specialist.


In most jurisdictions, physicians (in either sense of the word) need government permission to practice. Such permission is intended to promote public safety, and often to protect the public purse, as medical care is commonly subsidized by national governments.

All medical practitioners

Among the English-speaking countries, this process is known either as licensure as in the United States, or as registration in the United Kingdom, other Commonwealth countries, and Ireland. Synonyms in use elsewhere include colegiación in Spain, ishi menkyo in Japan, autorisasjon in Norway, Approbation in Germany, and “?δεια εργασ?ας” in Greece. In France, Italy and Portugal, civilian physicians must be members of the Order of Physicians to practise medicine.

In some countries, including the United Kingdom and Ireland, the profession largely regulates itself, with the government affirming the regulating body’s authority. The best known example of this is probably the General Medical Council of Britain. In all countries, the regulating authorities will revoke permission to practice in cases of malpractice or serious misconduct.

In the large English-speaking federations (United States, Canada, Australia), the licensing or registration of medical practitioners is done at a state or provincial level. Australian states usually have a “Medical Board,” while Canadian provinces usually have a “College of Physicians and Surgeons.” All American states have an agency which is usually called the “Medical Board”, although there are alternate names such as “Board of Medicine,” “Board of Medical Examiners”, “Board of Medical Licensure”, “Board of Healing Arts” or some other variation. After graduating from medical school, physicians who wish to practice in the U.S. usually take standardized exams, such as the USMLE for MDs, COMLEX-USA for DOs, the NBDE exams for dentists, the NBPME exams for podiatrists, or the NPLEX for naturopaths which enable them to obtain a certificate to practice from the appropriate state agency.

Specialists in internal medicine

Most countries have some method of officially recognizing specialist qualifications in all branches of medicine, including internal medicine. Sometimes, this aims to promote public safety by restricting the use of hazardous treatments. Other reasons for regulating specialists may include standardization of recognition for hospital employment and restriction on which practitioners are entitled to receive higher insurance payments for specialist services.