1. Pulmonology—Pulmonologists are lung doctors that focus on conditions like asthma and emphysema/chronic bronchitis (also called COPD). Interestingly, they are also experts in sleeping problems (often sleeping problems are related to breathing) with one of their major focuses being a condition called sleep apnea 2. Endocrinology—Endocrinologists are hormone and gland doctors. These doctors focus on diseases of the thyroid gland (either over or under-active thyroid), diabetes and other hormone conditions. Diabetes can be confusing, because most people with diabetes see their PCP, but there are instances where it may be preferable to see an endocrinologist for diabetes. 3. Cardiology—Cardiologists are heart and blood vessel doctors. These doctors focus on preventing heart attacks and treating patients who have had heart attacks. They also see patients that have a condition called Congestive Heart Failure (or CHF), where the heart does not pump as strong as it should and as a result patients with CHF tend to retain fluid in their legs and lungs. 4. Gastroenterology—Gastroenterologists are doctors of the digestive system (esophagus, stomach, small intestine, large intestine, pancreas and liver). Gastroenterologist is a rather long word, so it is often just abbreviated as GI doctor (for ‘Gastro-Intestinal’ doctor). They see patients who have problems with severe or chronic heart burn, indigestion, stomach pain, chronic diarrhea or constipation and a condition called irritable bowel syndrome. 5. Hepatology—Hepatologists exclusively focus on the liver. While GI doctors can also see patients with liver problems, Hepatologists typically see patients that have chronic or severe liver conditions. These conditions include Hepatitis A, B or C or people who actually have liver failure and may need a liver transplant. 6. Hematology/Oncology—Hematologist/Oncologists see patients with blood disorders and cancer. These two sub-specialties are generally lumped together and Hematologist/Oncologists will often see patients with blood disorders like anemia (low blood count) or cancer–breast, lung and colon cancers are the most frequent types of cancers that these doctors treat. Now these doctors are not surgeons. If a cancerous tumor needs to be surgically removed, this type of doctor will not perform the surgery. A separate surgeon will. The Hematologist/Oncologist will typically administer the chemotherapy to treat the cancer if it is called for. Often people with cancer see multiple types of doctors, with the Hematologist/Oncologist being just one of them. 7. Nephrology—Nephrologists are kidney doctors. They treat patients that have partial kidney damage (referred to as renal insufficiency) and kidney failure. When a person has kidney failure they may require dialysis to control the electrolytes (sodium, potassium, and calcium), water and waste products in their bodies. Nephrologists are the doctors that manage the dialysis. Another type of kidney doctor is an Urologist, but this specialty is not part of Internal Medicine and they treat different types of kidney problems—such as kidney stones. 8. Rheumatology—Rheumatologists treat conditions called ‘Autoimmune Diseases.’ An autoimmune disease is where the body’s own immune system attacks itself rather an outside bacteria or virus. Examples of autoimmune diseases are rheumatoid arthritis and lupus. Autoimmune diseases often cause pain and swelling in the joints, so rheumatologists are also joint experts and treat various joint conditions (e.g. gout). However, rheumatologists are not surgeons and they typically do not see patients that have joint injuries from sports or overuse—Orthopedic Surgeons typically see those types of patients. 9. Allergy/Immunology—Allergist/Immunologists perform allergy testing to see what substances or foods a person may be allergic to (e.g. pollen, mold, nuts) and administer allergy shots to desensitize a person to those substances, making their allergies less severe. They can also treat immune deficiency conditions. These are very rare conditions where the body’s immune system is under-functioning. 10. Infectious Disease—Infectious Disease doctors treat chronic and severe infections. Common infections that these doctors treat are HIV/AIDS, bone infections and severe skin infections. Fortunately, most infections that people have are short-lived, mild and are often treated by their Primary Care Physician—not an Infectious Disease doctor (e.g. strep throat, sinus infection). 11. Geriatrics—Geriatricians are doctors for the elderly. There is not a specific age where a person should start seeing a geriatrician, but these doctors typically see patients that are age 80 and above. They specialize in helping people with dementia (Alzheimer’s and other types) maintain their quality of life and are good at coordinating the many medications that the elderly take—preventing drug interactions and minimizing side-effects. Geriatricians may visit nursing homes to see their patients or even make house calls. Source
