Why are there so many of them?

You are having a problem with your foot, so you go to your doctor, who recommends you go to a specialist. Should you see a podiatrist, an orthopedist, or an orthopedic surgeon? This variety in specialization occurs throughout all areas of medicine. Understanding the differences between types of doctors can be extremely helpful in answering the question: Which one is the BEST one to help you?


To be accepted into medical school, you must have at least a four-year college degree. Medical school takes another four years to complete. After medical school, doctors must complete a residency in a specialty of their choice. Depending on the type of residency, it can last anywhere from three to nine years. After residency, if a doctor wants to focus on a specific area of their specialty or sub-specialize, they must complete a fellowship, which is an additional two to four years of training. So, a freshly minted doctor has anywhere from 13 to 21 years of training.

You might notice that your doctor has an MD or DO after their name. Either one is qualified to take care of you. The main difference is the approach they use to do so. A MD is a doctor of medicine, whereas a DO is a doctor of osteopathic medicine. MDs use a treatment method called allopathic, which is focused on treating disease symptoms by using remedies like drugs or surgeries. DOs’ technique is osteopathic, which focuses on a “whole body” approach. This means they address medical concerns from medical and lifestyle standpoints. They are required to take additional classes, usually 300-500 hours, focusing on how your skeletal system interacts with the rest of your body when you are sick. Most people only notice any difference if their primary care physician (PCP) is a DO. They’ll ask questions about the disease process, your lifestyle, and how it might affect your ability to become well.

Medical Doctor Specialties

A primary care physician is also called an internal medicine doctor, general internist, generalist, or internist. They are considered the general doctor for adults, meaning they take patient histories, do physical exams, make diagnoses, and prescribe medications. If something requires a more detailed care plan, they’ll refer you to a specialist who solely focuses on that item. Some internal medicine doctors specialize in sub-categories. When they do this, it means that they concentrate exclusively on that particular disease or body system.

These types of internal medicine doctors aren’t considered primary care physicians. Pulmonologists are internal medicine doctors that take care of conditions that affect your lungs and how your breathing can affect your sleep, like sleep apnea. Endocrinologists treat conditions related to your hormones and glands. Cardiologists focus on your heart and blood vessels. Gastroenterologists deal with your digestive system. Hepatologists care for conditions that affect your liver. Hematologists/Oncologists look after you if you have a blood disorder or cancer. Nephrologists take care of any kidney problems. Rheumatologists handle autoimmune disorders (diseases where your body’s immune system attacks itself). Allergists/Immunologists provide allergy testing and shots and treat conditions where your body’s immune system is under-functioning. Infectious disease doctors deal with chronic and severe infections (ex. HIV/AIDS). Geriatrics is an internal medicine doctor specializing in treating the elderly, usually people over 80.

There are numerous areas that doctors can specialize in that aren’t related to being an internal medicine doctor. One that many people are familiar with is Obstetricians/Gynecologists (OBGYNs). They concentrate on the female reproductive system, can care for pregnant women, and deliver babies. Some doctors practice obstetrics (taking care of pregnant women) and gynecology (female reproductive issues). Others only do gynecology, so it’s essential to clarify so you go to the right doctor depending on your need. Within OBGYN, there are several specialties, such as maternal-fetal medicine (take care of patients with high-risk pregnancies), reproductive endocrinology (assist with infertility issues), gynecologic oncology (deal with surgery for specific cancers, like breast, ovarian, endometrial and vulvar) and urogynecology (treat urinary conditions in women). Family Practice doctors are trained in internal medicine, pediatrics, and OBGYN, which means they can be the primary care physician for adults and children and deliver babies. Another area most people have heard of is Pediatricians, which are doctors that take care of children. Under pediatrics, you have the same specialties as adults, such as neurology, cardiology, hematology/oncology, ophthalmology, anesthesiology, and surgery. This means these doctors have concentrated on treating these areas for children only.

Neurologists treat disorders related to your brain and nerves. Psychiatrists treat you if you have a mental health issue. Subsets of psychiatrists focus only on the geriatric (elderly) or pediatric (young) populations. Addiction medicine doctors help people overcome repetitive behaviors like drug/alcohol dependency or eating disorders. Sleep medicine doctors evaluate you if you are having poor sleep. Dermatologists are doctors who focus on skin conditions. Physical medicine and rehab doctors help improve your body’s function if you have a chronic disability. Sports medicine doctors deal with preventing and treating injuries related to sports and exercise. Hospice and Palliative doctors help manage pain and maintain a quality of life as a person nears death. Preventive medicine doctors deal with broad issues that affect many people, and often they work in public health. Medical geneticists focus on hereditary disorders and genetic counseling/screenings.

Hospitalists are doctors who work only in the hospital and are in charge of a patient’s care from when they are admitted until they are discharged. This means they coordinate care between the patient’s PCP and any consulted specialists. Emergency Medicine doctors are trained in stabilizing critically ill patients and providing treatment for various conditions. Pathologists are doctors that examine biopsy specimens (small pieces of tissue that are viewed under microscopes). Radiologists review and interpret imaging tests, such as x-rays, ultrasounds, CT scans, MRIs, and PET scans. Radiation Oncologists are the doctors that provide radiation treatment for certain types of cancers. Electrophysiologists are cardiologists who have additional training in treating heart rhythm disorders. Interventional Cardiologists perform procedures that are non-surgical (don’t need to cut you open) and are specifically related to a person’s heart or blood vessels. Interventional Radiologists are similar, except they use real-time x-rays as a guide during procedures. Often the procedures they perform are related to blood vessels, kidneys, and implanting specific medical devices. Anesthesiologists are the doctors that provide sedation for surgery and procedures.

Surgeons are doctors that specialize in performing different operations. General surgeons typically perform numerous surgeries that aren’t focused on a particular body area. Similar to internal medicine doctors, general surgeons can sub-specialize. A cardiothoracic surgeon operates only on your heart, lungs, or chest, whereas a vascular surgeon works on the blood vessels throughout your body. Cosmetic and reconstructive surgeons, also known as plastic surgeons, can do facial surgery, liposuction, breast surgery, and some types of hand surgery. Colorectal surgeons used to be known as proctologists and operate on your colon. Surgical Oncologists remove tumors throughout your body. Transplant surgeons perform organ transplants. Trauma surgeons try to fix injuries that your body sustains, typically from objects that penetrate your body but can be from blunt force injuries (internal damage without an apparent exterior wound). Surgical Endocrinologists deal with tumors or growths on the glands of your body.

Several other types of surgeons are not sub-specialties of general surgeons. Orthopedic Surgeons perform surgery on bones and joints. Within this type of surgery, many doctors concentrate on specific areas, like hands, shoulders, knees, hips, spines, sports medicine, and orthopedic oncology. Neurosurgeons are doctors who operate on your brain and spinal cord. Bariatric surgeons perform surgery on your stomach or intestines to help you if you are overweight. Urologists can address issues related to your kidneys, bladder, and male genitals. Otolaryngologists, also known as ear, nose, and throat (ENT) doctors, can do surgery on your sinuses, tonsils, and vocal cords. Ophthalmologists see patients experiencing vision problems and can perform procedures to correct these. Oral surgeons are dentists who specialize in treating a wide range of conditions related to your mouth, teeth, and gums. Microsurgeons perform reconstructive surgery under magnification using delicate instruments and exact techniques.

Non-Medical Doctor Specialties

Some healthcare providers receive extensive training in certain areas but aren’t medical doctors. You can see them for conditions related to their area of expertise, but they might not be able to treat every illness that falls under that area or have certain restrictions that medical doctors don’t have. Psychologists and counselors are an example of this. Psychologists have a Ph.D., and counselors usually have a Master’s degree in social work, which means they cannot prescribe medications. So, they will work with a psychiatrist to provide this service to their patients when needed. Podiatrists specialize in treating conditions related to feet and have the capability of prescribing certain medications and performing some surgeries. Optometrists can treat some eye conditions but can’t perform surgery or prescribe certain medications.

With all of these different specialties, understanding what each one does can be confusing. Hopefully, this list, while not entirely inclusive, will give you a little more insight into who is providing care for you or a loved one. Don’t hesitate to ask if you are unsure why a doctor is consulted. Since the human body is so complex, it’s good to have doctors who focus on a particular area. Although there are many different types of doctors, each has its own place in taking patients.