Most of us are familiar with MD after a doctor's name. This stands for doctor of medicine and signifies that this person has completed four years of medical school. But would you know if your doctor is a DO? And what about the other people checking vitals, writing prescriptions, and filling in charts—PAs and NPs—what type of training do they have and what services can they offer?

MDs and DOs

MDs and DOs Are Similar

A DO is a doctor of osteopathic medicine. According to the American Osteopathic Association, approximately 5% of physicians in the US are DOs.

MDs and DOs are similar in many ways. Here are some requirements that both MDs and DOs must complete:

  • Earn a four-year undergraduate degree with a strong education in science
  • Complete four years of medical school
  • Complete residency programs, which involves three to six years of additional training
  • Pass state licensing exams (obtain licenses to prescribe medicine and perform procedures)
  • Practice in accredited hospitals and medical centers
  • Earn continuing education units to remain certified

MDs and DOs Differ

There are also some distinctions between these types of physicians:

  • Osteopathic medical schools focus on primary care medicine. The majority of DOs practice in areas of primary care, such as pediatrics, family practice, obstetrics/gynecology, and internal medicine.
  • Rather than emphasizing symptoms and laboratory findings, DOs are trained to spend more time considering the broad range of factors affecting health, such as home and work environments. In practice, however, it is not unusual to find MDs who are just as holistic, if not more so, than their DO colleagues.
  • DO's education emphasizes preventive health care.
  • DOs receive extra training in the musculoskeletal system. This system consists of interconnected muscles, tendons, ligaments, and bones. DOs are trained in a philosophy of medicine that places great emphasis on the importance of this system to the maintenance and restoration of health.
  • Probably the most defining feature of osteopathic medicine is a technique called osteopathic manipulative treatment (OMT). With OMT, DOs use their hands to manage their patient’s injuries and illnesses. MDs do not practice this technique and rarely use their hands to treat.

Physician Assistants

A physician assistant (PA) is a health professional who is licensed to practice medicine under the supervision of a physician. A PA can do the following:

  • Obtain a medical history and perform a physical exam
  • Diagnose and treat illnesses
  • Order and interpret tests such as lab work and x-rays
  • Counsel on preventive health and lifestyle practices
  • Assist in surgery
  • Prescribe medications in most states (47 states as well as Washington, DC and Guam)

A PA can work in any area of medicine, but the majority of PAs work in primary care medicine (pediatrics, family practice, obstetrics/gynecology, and internal medicine). About 19% of PAs work in surgical-related fields.

Education for PAs

To become a PA, one must complete an accredited PA educational program and pass a national certification exam. Once certified, PAs take continuing medical education classes and are retested on their skills regularly. The typical PA program is 24-25 months long. Entry requires at least two years of college and some healthcare experience. The majority of students have a BA/BS degree and 3-4 years of healthcare experience before admission to a PA program.

PA education is designed to complement physician training. Education consists of classroom and laboratory instruction in the basic medical and behavioral sciences as well as clinical rotations in primary care fields, surgery, emergency medicine, and geriatric medicine.

Nurse Practitioners

A nurse practitioner (NP) is a registered nurse (RN) with a master's degree in nursing and clinical training in a health care specialty area. The services a NP can provide vary depending on each state's regulations. In general, NPs can do the following:

  • Obtain a medical history and perform a physical exam
  • Diagnose, treat, and monitor illnesses and injuries
  • Order and interpret tests such as lab work and x-rays
  • Prescribe medications, in most states
  • Counsel on preventive health and lifestyle practices

Nurse practitioners can work in primary care (pediatrics, family practice, obstetrics/gynecology, and internal medicine) or specialty areas of medicine, such as emergency medicine, oncology, and psychiatry.

Education for NPs

The path to becoming a NP usually begins with nursing school, followed by licensure as an RN. After a few years of work experience, an RN can apply to a master's degree program in nursing (generally 1-2 years of school and a supervised internship). Most NPs are nationally certified in their specialty area.

Knowing When to Say When

While PAs and NPs can perform many of a doctor's functions, an essential part of their training is knowing when to defer to a physician. Exactly what a NP or PA can handle and what they pass onto the physician varies greatly with training, experience, state law, and the supervising physician's practice. Generally, a physician handles patients with complicated medical issues or problems outside of the PA's or NP's scope of knowledge.