What Is a Physician?

What It Takes to Become a Medical Doctor

Female doctor looking at laptop screen while preparing report at desk in clinic

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A physician (also known as a medical doctor, medical practitioner, or simply a doctor) is a professional who is trained and licensed to practice medicine. There are many different types of physicians, some of whom opt to specialize in fields such as pediatrics, gynecology, or surgery. Those who assume the responsibility of providing continuous, comprehensive care to individuals or families are referred to as general practitioners (GP).

Whatever the specialty, the route to becoming a physician is similar. It typically involves a bachelor's degree from an accredited college, medical school, residency, and licensure within your state. The duration of training can vary as can the schools and programs you enter.

You can opt to attend a medical school that offers a doctor of medicine (MD) degree or a doctor of osteopathic medicine (DO) degree. Upon completion of your residency, you can pursue additional training in a medical subspecialty through an accredited fellowship program.

Both MDs and DOs are qualified to practice medicine; the main difference is that osteopathy involves an alternative practice known as osteopathic manipulative treatment (OMT) believed to diagnose and treat certain ailments.


The definition of a physician can vary from one country to the next. In the United Kingdom, for example, a physician is either a GP or an internist (a doctor trained in internal medicine). In the United States, a physician is any doctor of medicine.

A physician is trained to diagnose, treat, manage, and prevent diseases, injuries, and physical or mental impairments. Physicians must achieve the highest level of competency in not only the academics of medicine (including anatomy, biology, physiology, and pharmacology) but the ideals of medicine as embodied in part by the Hippocratic Oath (to "help the sick" and "first do no harm").

This includes adherence to medical ethics, "best practices," and the prescribed codes of conduct. Physicians will also direct care based on peer-reviewed, evidence-based science as outlined in the clinical guidelines of accredited medical societies (such as the American College of Cardiology and National Comprehensive Cancer Network) or public health authorities (such as the U.S. Preventive Services Task Force or the Centers for Disease Control and Prevention).

If a physician believes it necessary to sway from the guidelines, he or she will do so based on clinical experience and informed judgment, weighing the benefits and risks of treatment as well as the legal and ethical implications.

In recent decades, the profession of medicine has moved away from the patriarchal model of medicine (where the doctor directs care) to one in which patients have a voice in the procedures that will submit to and those they won't.

To this end, physicians must be capable communicators, providing the patient with all of the information needed to make a fully informed choice without coercion or judgment.

With medicine and technologies ever-changing, physicians must also maintain continuing medical education (CME) training to ensure that their knowledge is current and to renew their licenses and board certifications.

Procedural Expertise

Physicians diagnose and treat injuries or illnesses. Among their duties, they perform physical exams, take medical histories, prescribe medications, and order, perform, and interpret diagnostic tests.

They will also counsel their patients on general health and wellness (including diet, exercise, and smoking cessation) and implement preventive measures to ensure ongoing good health.

Physical Examination

A physical exam with a review of a patient's medical history is the first step in the diagnostic process. The exam may be routine (such as an annual physical), used for screening purposes, or used to diagnose and monitor an illness. A physical exam typically involves four techniques: 

  • Inspection, using the naked eye
  • Auscultation, using a stethoscope
  • Palpation, applying hand or finger pressure to determine the condition of an underlying organ
  • Percussion, tapping of a body part to determine the size, consistency, and borders of an organ

Other tests—like a blood pressure reading, reflex test, otoscopic exam (to view inside the ear), and ophthalmoscopic exam (to view inside the eye)—may also be used.

Based on the findings, the physician will order tests and procedures to explore the possible causes of your symptoms.

Lab Tests

Physicians will routinely order tests to evaluate body fluids, tissue samples, or even the composition of your breath. The types of tests can be broadly classified by their purpose:

Samples may be obtained via a blood draw, saliva swab, lumbar puncture, biopsy, amniocentesis, or resected organ. The samples would then be sent to a pathology lab where they would be evaluated visually, chemically, microscopically, and sometimes molecularly.

Imaging Studies

Medical imaging involves various technologies that provide a doctor with an indirect look inside the body. The most common can be broadly described as follows:

  • Radiography, including X-ray, fluoroscopy, and DEXA scan
  • Ultrasound, including Doppler ultrasound and echocardiogram
  • Magnetic resonance imaging (MRI), including a cardiac MRI
  • Tomography, including computed tomography (CT) and positron emission tomography (PET)
  • Nuclear medicine, including a nuclear stress test, SPECT scan, and bone scan


Endoscopy is a technique involving the use of a scope to directly view internal structures. Endoscopy generally takes specialized training for a physician to perform the procedure. Some may be conducted in an office; others may require a hospital or inpatient facilities. Examples include:

In addition to diagnosis, endoscopy may aid in the removal of lesions, polyps, or tumors or to resect (cut away) or ablate (remove) diseased tissue.


Physicians will commonly prescribe medications in the course of their practice. These not only include pharmaceutical drugs that require a doctor's prescription but over-the-counter (OTC) drugs that you can purchase at the drugstore.

The proper use of a prescription drug is largely directed by the terms of its approval by the U.S. Food Administration (FDA). Medications are sometimes used off-label (meaning for purposes other than those approved by the FDA) if there is evidence of a benefit. One such example is the use of the female fertility drug Clomid (clomiphene) in men with a low sperm count.

Among the drugs a physician may prescribe or recommend:

  • Pharmaceutical drugs are grouped by classes and typically require years of safety and efficacy research before they are approved.
  • OTC drugs like aspirin and antihistamines are not as stringently regulated and are allowed to be sold under the GRAS/E (generally recognized as safe and effective) classification.
  • Dietary supplements, including vitamins, herbal remedies, and bodybuilding supplements, are substances that are considered safe and potentially beneficial but can in no way "cure" a disease or medical condition.


The selection of an appropriate treatment is based on a physician's clinical experience, the prescribed guidelines, and the needs, limitations, or desires of the individual patient. If a certain treatment is beyond the scope of a doctor's practice, the patient will commonly be referred to another specialist.

The clinical practice guidelines are formulated and reviewed by a panel of experts under the auspices an accredited medical body. The guidelines may be revised whenever new research has shown that a certain drug, treatment, or diagnostic approach is superior or that a traditional approach is either harmful or inferior.

Every medical specialty and subspecialty will have clinical guidelines to help direct treatment decisions. Examples include the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) from the American Psychiatric Association (APA) or HIV screening recommendations issued by the U.S. Preventive Services Task Force (USPSTF).


After completion of medical school, physicians will usually further their education by choosing a medical specialty. Depending on the specialty, you may need to undergo several years in a medical residency program with an additional one or more years in fellowship training. From start to finish, some specialties may take up to 18 years of education and training.

Some specialties fall under broader fields of medicines such as internal medicine or surgery. Others are their own specialty. Each specialty has its own board certification body, most of which full under the umbrella of the American Board of Medical Specialties (ABMS).

Currently, the ABMS recognizes 24 different medical specialties:

  • Allergy and Immunology
  • Anesthesiology 
  • Colon and Rectal Surgery
  • Dermatology 
  • Emergency Medicine 
  • Family Medicine 
  • Internal Medicine 
  • Medical Genetics and Genomics 
  • Neurological Surgery 
  • Nuclear Medicine
  • Obstetrics and Gynecology 
  • Ophthalmology 
  • Orthopedic Surgery 
  • Otolaryngology/Head and Neck Surgery 
  • Pathology 
  • Pediatrics
  • Physical Medicine and Rehabilitation 
  • Plastic Surgery 
  • Preventive Medicine
  • Psychiatry and Neurology 
  • Radiology
  • Surgery 
  • Thoracic Surgery 
  • Urology

Training and Certification

The training needed to become a physician is extensive compared to most careers. The educational pathway can vary significantly based on the type of medicine you decide to practice. With that being said, there is a common structure to the educational and training process.

Undergraduate Studies

All doctors must start by obtaining an undergraduate degree from a four-year college or university. While some colleges offer dedicated pre-medicine ("premed") programs, you can as easily meet the entry requirements of a medical school by completing the prerequisite courses in advanced math, chemistry, biology, physics, and social science.

You would also need to pass the Medical Competency Aptitude Test (MCAT) available from January to September. Many people will take the MCAT the year they intend to graduate, but others start sooner. This along with your application, transcripts, grade point average, and interview is all that a medical school needs to assess your eligibility.

You can take the MCAT up to three times in a single testing year or four times over two consecutive years. Be aware, however, that the medical school will see all of your test results and make its decision based on them.

Medical School

There are 35 medical schools that offer DO degrees in the United States and 141 that offer MD degrees. Deciding which to attend is purely a personal choice. Although osteopathy is considered by some to be the "more holistic" of the two practices, the core medical curriculum is pretty much identical.

Upon entry, you would spend the first two years mainly in the classroom and laboratory. The coursework would cover anatomy, biology, pharmacology, pathology, and other medical sciences. Students would also study the practice of medicine and the legal and ethical issues related to healthcare.

Much of the second two years would be spent doing clinical rotations in different medical facilities under the supervision of an experienced physician. The rotations offer you broad exposure to different fields of medicine, including neurology, radiology, pediatrics, and family medicine.


Upon graduation from medical school, you would start a residency program. The process would actually start in your third year of medical school as you begin making applications to the programs you are interested in.

The selection of residents traditionally occurs on the third Friday of March, known as National Residency Match Day (NRMD). This is when most residency programs release their acceptance list to applicants.

The national Match Days for osteopathy, ophthalmology, urology, and plastic surgery occur on different days.

Depending on medical specialty, a residency can last anywhere from three to eight years. Most residents complete their programs in hospitals under the supervision of an attending physician. The first year is typically devoted to general practice, referred to an internship.

Residents earn a small salary to cover basic living expenses (usually between $40,000 and $60,000 per year).

Licensure and Certification

All physicians are required to be licensed in the state in which they intend to practice. To do so, you would need to graduate from medical school, pass your residency training exam, and pass a national exam (and sometimes a state exam). Contact your state medical board for details.

Physicians with an MD degree must complete a three-part test called the U.S. Medical Licensing Examination (USMLE). Those with a DO degree can opt to take the Comprehensive Osteopathic Medical Licensing Examination (COMLEX) instead.

Although not required, physicians are encouraged to obtain board certification in their field of practice. This typically involves a multiple-choice exam followed at a later date by an oral exam covering the same topics.

Having board certification can increase your job opportunities and is required by certain hospitals, research facilities, and academic institutions.

Physicians from other countries must complete the Educational Commission on Foreign Medical Graduates (ECFMG) to practice in the United States. The process entails paperwork to verify your degree attendance in medical school as well as an exam to confirm language and medical skills.

Appointment Tips

The patient-doctor relationship is central to the practice of medicine. It means that you, as the patient, have as much input into the direction of your care and have the right to know everything your condition so that you can make an informed choice. This includes knowing as much as you can about your doctor.

A good place to start is by checking the doctor's credentials. You can do this by doing an online search with the ABMS verification portal and using the DocInfo website managed by the Federation of State Medical Boards. Together, these can provide you information about the doctor's education, certifications, licenses, and any civil, legal, or disciplinary action filed against the physician.

When you meet, don't be shy to ask about the doctor's experience. This includes asking how much of the practice is devoted to your condition.

Also, use the time to ascertain how the doctor interacts with you. Does the doctor listen actively and answers your question fully and in a language you understand? Or does the doctor do most of the talking in jargon you can barely understand?

It often helps to write down questions in advance so that you don't forget them and to take notes so that you have a record of your discussion. If at any time you feel uncertain about the course of treatment, never hesitate to seek a second option from a qualified medical professional

Equally important is your control over costs. In addition to ensuring the doctor accepts your health insurance, check to see if the labs or facilities used are in-network or out-of-network providers. If the costs are beyond your reach, a physician can often work with your insurer or point you in the direction of copay or financial assistance programs. Never be afraid to ask.

A Word From Verywell

It takes dedication to become a physician. In additional the extensive training, doctors invariably put in long hours for many years and often experience burnout along the way.

Most doctors work 50 to 60 hours per week at the very least. A typical day might include six to eight hours seeing patients in an office with one to two hours making rounds in hospitals. Many specialties require you be on-call or to work night shifts and weekends.

It is for this reason that you need to carefully consider which field of medicine is right for you. Ideally, it would be one you can remain passionate about while providing you the work-life balance you need. The rewards, both personal and financial, can make it all worth it.

According to the Bureau of Labor Statistics, physicians in the United States made a median annual income of $203,880 in 2018. Some specialists, including surgeons and oncologists, can make well in excess of $500,000 per year.

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