What Are the Different Types of Pediatric Internal Medicine?

Doctors of pediatric internal medicine may choose to continue their studies by choosing one or more sub-specialties. Like physicians who concentrate on adult diseases, pediatricians may select a medical specialty from a number of areas. Endocrinology, gastroenterology, infectious diseases, hematology, oncology and rheumatology are among the most popular sub-specialties chosen by physicians practicing pediatric internal medicine.

Endocrinologists specialize in diseases affecting the glands and the body's production of hormones. Juvenile diabetes is one example of a glandular disease; it is caused by the inability of the pancreas to manufacture an adequate amount of insulin, which the body needs to utilize sugar in the blood. Other conditions a pediatric endocrinologist might treat include disorders of the thyroid, pituitary or adrenal glands. An endocrinologist may also treat patients with disorders involving the testes or ovaries, especially issues that develop around the time of puberty. Pediatric endocrinologists also treat children who are not growing properly or who have problems with their weights.

Gastroenterologists treat problems involving the digestive system, focusing primarily on disorders affecting the bowels, stomach and intestines. The practice of gastroenterology also includes disorders affecting the gallbladder, liver and pancreas. Jaundice, hepatitis and colitis are among the diseases that may be treated by a pediatric gastroenterologist.

Doctors who specialize in infectious diseases concentrate on illnesses that suppress the immune system. The illnesses may be caused by a virus, parasites, bacteria or fungi. Infectious disease specialists are experts in how infections are spread, how the body's immune system fights infection and the drugs used to treat infections. Some pediatric infectious disease doctors choose to specialize in patients born with human immunodeficiency virus (HIV). Others focus on diseases that are most prevalent among children, such as diphtheria and measles.

Hematologists treat diseases that affect the blood, such as sickle-cell disease and anemia. Oncologists are specialists in the treatment of cancer. Some doctors of pediatric internal medicine choose to combine the two and choose pediatric hematology/oncology as a sub-specialty. These doctors treat children with leukemia, tumors and cancers.

Although rheumatology is primarily the study of the muscles, bones and joints, some pediatric rheumatologists incorporate the sub-specialty with pediatric internal medicine. Diseases such as juvenile rheumatoid arthritis are caused by a defect in the body's immune system, even though the effects are most noticeable in the patient's joints; almost 300,000 children in the U.S. suffer from juvenile arthritis. Pediatric rheumatologists also treat patients with rheumatic fever, Kawasaki's disease, lupus and Raynaud's disease.