Subspecialties for internal medicine residents

Subspecialties for internal medicine residents

Learn about the various specialized fields in internal medicine, their significance in healthcare, and how they contribute to patient care.

Let’s start with the basics. What is an internist doctor?

An internal MD is a physician who deals with a broad spectrum of adult illnesses and is specialized in the diagnosis and treating of chronic illness and disease prevention. However, because they receive primary care training on internal medicine, they also manage wellness, substance abuse, and mental health.

General internists are often responsible for the lifelong care of their adult patients, taking care of them in an ambulatory scenario and as inpatients in the event of hospitalization. Being a general internist means you can build long-term and rewarding relationships with patients, looking after their wellbeing and health for the duration of their adult life.

However, that’s not always the end result for internal medicine residents. When you choose to specialize in internal medicine, you’re opening the door to many different subspecialties. If you’d like to learn about the different options open to you in internal medicine, then read on.

What is a subspecialty?

A subspeciality is a narrow field of expertise that a doctor chooses to train and gain experience in. Instead of covering general internal medicine, an internist with a subspeciality will focus on patients with symptoms or a diagnosis that falls within the chosen subspeciality.

To subspecialize, the doctor must complete a period of training known as a fellowship. The length of training varies according to the subspecialty, ranging from three to eight years. Once the training is complete, the doctor can become a consultant in their chosen field.

As with a general internist, an internal MD with a subspecialization will often be called upon as a consultant for patients with puzzling or complex diagnostic problems.

List of internal medicine subspecialties

If you’re a qualified internal MD, there are many subspecialties in which you can choose to train. The list that follows isn’t exhaustive but will show the most common choices:

Adolescent medicine

Internist doctors specializing in adolescent medicine deal with adolescent and young adult physical, psychological, social, and sexual development. These physicians work with patients who are transitioning from childhood to adulthood. While this may sound similar to pediatrics, adolescent medicine specialists don’t work with children until they reach the age of 10 or 11 years old.


Physicians who specialize in allergy and immunology deal with the prevention, diagnosis and treatment of disorders with the human immune systems, dealing with health issues such as asthma, allergies and immunologic disorders. This specialization can be clinical, dealing with patients directly, or focused more heavily on research and laboratory work.

Cardiovascular disease

Also known as cardiologists, these physicians are one of the most well-known specializations in internal medicine. Doctors who specialize in cardiovascular are experts in diseases of the heart and blood vessels. Cardiologists also focus on preventative measures in treating and managing conditions including coronary artery disease, heart rhythm abnormalities, and heart failure.


Endocrinologists are hormone and gland doctors. They are experts in the hormonal regulation of normal physiology, including the pituitary, thyroid, adrenal, pancreas, ovaries/testes, and target tissues. This specialty focuses on diseases of the thyroid gland, diabetes, and other hormone conditions. The specialization favors MDs with a strong research background, as laboratory tests play a large role in diagnosing and managing these diseases.


Gastroenterologists, or Gis, research, diagnose and treat disorders of the digestive system (esophagus, stomach, small intestine, large intestine, pancreas, and liver). Some commonly treated conditions include ulcers, liver disease, and abdominal pain.


Geriatric doctors deal primarily with elderly patients. There is no specific age when a person should start seeing a geriatrician; however, these physicians generally see patients aged 80+. This specialization focuses on conditions specific to aging, including preventive medicine, management of patients in long-term care, and dementia. A geriatric doctor needs to have a deep knowledge of the aging process and look after the patient’s wellbeing as a whole.


Hematologists are experts who specialize in the diagnosis, treatment, and prevention of disorders affecting the blood, bone marrow, and immunologic, hemostatic, and vascular systems. Dealing with disorders, such as hemophilia, anemia, and leukemia, these MDs usually work closely with oncology physicians.

Infectious disease

Infectious disease specialists focus their practice on diagnosing and treating diseases caused by microorganisms. While mild and common infections, such as strep throat and sinus infections, can be dealt with by a primary care physician, infectious disease doctors diagnose and treat chronic and severe disorders such as bone infections and HIV.


Internists who go on to specialize in nephrology focus their practice on treating disorders of the kidney, including those that affect kidney function, kidney stone formation and blood pressure regulation. They work with patients who have mild conditions as well as those with more complex or advanced diseases.


Medical oncologists are most commonly known for treating cancer; however, they also deal with noncancerous tumors. Oncologists usually work closely with surgeons and other physicians to treat cancers, while also administering therapies. Often working closely with long-term patients, this is a good specialization if you enjoy dealing with people. Oncologists often go on to focus on certain types of cancer or specific therapies but begin their journey with a more broad interest.

Pulmonary disease

Pulmonary specialists treat patients with diseases of the lungs, focusing on respiratory disorders, including asthma, emphysema/chronic bronchitis (also called COPD) and pulmonary hypertension. They also diagnose and treat sleeping problems with a significant focus on sleep apnea.


A rheumatologist is a physician who deals with the diagnosis and treatment of diseases that affect the joints, muscles, and related tissues. Physical examination skills are the priority for this specialization. Autoimmune diseases, such as rheumatoid arthritis and lupus, are treated by rheumatologists due to the joint pain caused by these conditions.

What are the most popular internal medicine subspecialties?

According to Locum Jobs Online list of medical specialties, the most popular specializations are:

  • Medical Oncology
  • Geriatrics
  • Pulmonology
  • Gastroenterology
  • Rheumatology
  • Cardiology

However, when it comes to choosing a specialization, MDs should consider their own personal interests and skills. If you’re an amazing researcher, something lab-based like allergy/immunology or infectious disease may fit you well. However, if you’re more of a people person, you may prefer long-term care for individual patients such as adolescent medicine, geriatrics, or oncology. 

What are the highest paying internal medicine subspecialties?

According to the fourth annual Physician Compensation Report, the highest paid internal medicine subspecialities are:


As with all jobs, the salary for both non-specialized and specialized internists will vary depending on city, state and country, and experience. Internal medicine MDs should expect to see their compensation increase as their experience does.

How do I choose an internal medicine subspecialty?

There is no hard and fast rule to picking the right subspecialty. When deciding where to focus your time and training, you should consider what areas of medicine you enjoy, which aspects of the job you like the most and where your natural skills lay.

If you’re looking to start your journey as an internal medical doctor, then take your first steps here and join our MD program. MUA has an integrated, systems-based curriculum that parallels the training you would receive at a top U.S. medical school. Find out what makes the MUA curriculum so special and why you should choose us for your education.

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