Who Is an Endocrinologist?
An endocrinologist is a physician who specializes in endocrinology, a branch of medicine devoted to the study of hormonal glands and the diseases and disorders that affect them. The specialty involves the evaluation of a wide range of symptoms in relation to a deficiency or excess of hormones. Many of these conditions are chronic (meaning they persist over a long time) and require ongoing and even lifelong management.
An endocrinologist is first trained in internal medicine, pediatrics, or gynecology before specializing in endocrinology. In the United States, the typical training involves four years of college, four years of medical school, three years of residency, and two years of fellowship.
Endocrinologists are in high demand with fewer than 4,000 actively practicing the United States, according to a 2014 study in the Journal of Clinical Endocrinology and Metabolism.
Endocrinology is a subspecialty of internal medicine whose function is to evaluate how hormones can affect metabolism, growth, weight, sleep, digestion, mood, reproduction, sensory perception, menstruation, lactation, and organ function, among other things.
Although every organ system secretes and responds to hormones, endocrinology focuses primarily on the organs of the endocrine system, specifically
- Adrenal glands, two glands situated atop the kidneys that secrete cortisol, the body’s main stress hormone
- Hypothalamus, a part of the lower middle brain that tells the pituitary gland when to release hormones
- Ovaries, the female reproductive organs that produce female sex hormones
- Pancreas, an organ in the abdomen that secretes the hormones insulin and glucagon
- Parathyroid, four glands in the neck that play a key role in bone development
- Pineal gland, a gland in the center of the brain that helps regulate sleep patterns
- Pituitary gland, often called the “master gland” because it influences the function of all other glands
- Testes, the male reproductive glands that produce male sex hormones
- Thymus gland, an organ in the upper chest that influences the development of the immune system early in life
- Thyroid gland, a butterfly-shaped organ in the neck that regulates metabolism
Any dysfunction of these organs can influence how much or little of a hormone is produced. Moreover, because the endocrine organs influence each other, the dysfunction of one organ can have a knock-on effect and trigger multiple hormonal imbalances.
Endocrine disorders may be caused by disease, injury, infection, or benign or cancerous growth. There are also genetic disorders that can affect the normal function of a gland. Failures in the endocrine feedback loop (the system in which endocrine glands respond to external stimuli or each other) can also lead to imbalances.
Among the conditions an endocrinologist can treat (or participate in the treatment of):
- Adrenal disorders, including Addison’s disease and Cushing’s disease
- Cancers, such as thyroid cancer, pancreatic cancer, ovarian cancer, and testicular cancer
- Developmental and growth problems in children, including delayed puberty, precocious puberty, short stature, gigantism, and disorders of sexual differentiation (DSD)
- Diabetes, including type 1 diabetes, type 2 diabetes, and gestational diabetes
- Gynecological disorders, such as premenstrual syndrome (PMS), amenorrhea, polycystic ovary syndrome (PCOS), endometriosis, and symptoms of menopause
- Infertility, often influenced by sex hormones in both men and women as well as adrenal and thyroid hormones
- Multiple endocrine neoplasia type 1, a rare disorder that causes the development of tumors in the endocrine glands
- Osteoporosis, a condition commonly linked to estrogen deficiency, menopause, hyperthyroidism, and low testosterone
- Paget’s disease, a disease that disrupts the replacement of old bone tissue with new bone tissue
- Pituitary tumors, most often benign
- Thyroid diseases, including hyperthyroidism, hypothyroidism, Grave’s disease, and Hashimoto’s thyroiditis
Depending on the condition, an endocrinologist may work alone or with other medical professionals, including gynecologists, neurologists, oncologists, osteopathic surgeons, pediatricians, and primary care physicians.
Because endocrinology is such a vast and diverse field, some endocrinologists will choose to limit their practice to specific conditions, populations, or procedures. Examples include:
- Diabetes and metabolism
- Endocrine oncology (involving cancer)
- Endocrinology nuclear medicine
- Gender reassignment
- Neurosurgical endocrinology
- Pediatric endocrinology
- Reproductive endocrinology (a.k.a. fertility specialists)
- Thyroid disease
Training and Certification
Endocrinologists are physicians and therefore must obtain a medical degree as either a doctor of medicine (MD) or doctor of osteopathic medicine (DO). The first two years of medical school are primarily devoted to classroom studies. The final two years involve clinical rotations in different hospitals to gain exposure to the various fields of medicine.
Upon completion of medical school, graduates must pass the United States Medical Licensing Exam (USMLE) to obtain a license in the state in which they choose to practice. Thereafter, they would begin their postdoctoral training by completing a three-year residency in internal medicine, pediatrics, or gynecology.
Near the end of the residency, the endocrinology candidate would apply for a two- to three-year fellowship in endocrinology. Fellowship programs can vary, with some providing general training. while others focus on pediatrics or reproduction and infertility.
Many hospitals require endocrinologists to be board certified.
In order to renew a medical license, an endocrinologist must participate in continuing medical education (CME) programs and maintain a certain number of study hours. Depending on the Coutry and medical subspecialty, licenses are renewed every seven to 10 years.
Endocrinologists often choose the profession because it doesn’t involve just one organ system or disease. Rather, endocrinology looks at the interrelationship between multiple organs and how they each contribute to a disease. The profession demands three-dimensional thinkers who are naturally curious and able to look at a problem for all sides.
The practice itself typically operates during normal office hours. Most tests and procedures are conducted in-office. Unless the practitioner specializes in surgery or cancer treatment, the more invasive procedures are standardly referred to an outside specialist.
According to the annual Medscape Compensation Report, endocrinologists in the United States earned a median income of $212,000 in 2018. Roughly 73 percent operate private practices in a profession largely dominated by women.
- Bornstein, S.; Allolio, B.; Arlt, W. et al. Diagnosis and Treatment of Primary Adrenal Insufficiency: An Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2016 Feb;101(2):364-89. DOI: 10.1210/jc.2015-1710.
- True, M.; Folaron, I.; Wardian, J. et al. Leadership Training in Endocrinology Fellowship? A Survey of Program Directors and Recent Graduates. J Endocrine Soc. 2017 Mar;1(3):174-85. DOI: 10.1210/js.2016-1062.
- Vigersky, R.; Fish, L.; Hogan, P. et al. The Clinical Endocrinology Workforce: Current Status and Future Projections of Supply and Demand. J Clin Endocrinol Metabol. 2014 Sept;99(1):3112-21. DOI: 10.1210/jc.2014-2257.