Endocrinology is a medical specialty whose practitioners (endocrinologists) diagnose and treat diseases and deficiency states of the thyroid, pancreas, ovaries and other glands. These organs manufacture chemicals called "hormones" and release them into the bloodstream to regulate various body processes. Since many of the glands and their hormones function in a coordinated manner we often speak collectively of an "endocrine system."

The Society of Endocrinology describes the medical specialty in the following way:

"Endocrinology is the study of hormones. At its simplest, a hormone is a chemical messenger from one cell (or group of cells) to another. Hormones are released (secreted) in the body and have an effect on other parts of the body. The effect is to communicate with possibly distant parts of the body."

While a complete discussion of Endocrinology is beyond the scope of this specialty description, here are brief summaries of the major endocrine glands, their best-known hormones and what they do (generally, over-and under-activity of these glands would cause too much or too little of these hormone effects).

1. The Pineal Gland located in the brain manufactures and releases melatonin which assists our adaptation to daily sleep-wake and dark-light cycles, thus being involved with jet lag and seasonal affective disorder (SAD).
2. The Pituitary Gland (a.k.a. "Master Gland" since it controls so many others) located in the brain manufactures and releases growth hormone (controls normal growth and development) and various "stimulating hormones" such as Thyroid Stimulating Hormone (TSH) and Ovarian Follicle Stimulating Hormone (FSH) that control the function of the different "stimulated" target glands.
3. The Thyroid Gland located in the neck manufactures and releases thyroid hormone which regulates metabolism -- i.e., how fast, slow or efficiently the body uses energy or accomplishes its various processes, including the generation of heat (so that a common symptom of overactivity is feeling too hot and energetic, and underactivity feeling too cold and sluggish). The Thyroid also manufactures Calcitonin which works with parathyroid hormone to regulate calcium levels.
4. The Parathyroid Gland located in the neck manufactures and releases parathyroid hormone (a.k.a. parathormone) which works with the thyroid's Calcitonin to regulate calcium levels. Overactivity elevates the blood calcium levels, a risk for osteoporosis and kidney stones.
5. The two Adrenal Glands located in the abdomen atop each kidney manufacture and release a number of different hormones including cortisol, adrenalin, aldosterone, and sex hormones, and thereby have numerous effects including salt, water and blood pressure balances and responses to stress and inflammation, all of which could be thrown off balance by over- and underactivity.
6. The Pancreas located in the abdomen manufactures and releases insulin and glucagon which regulate blood sugar metabolism. Type I Diabetes is a well-known effect of insulin deficiency, although people affected by the more common Type II Diabetes typically have some amount of insulin but it doesn't work well (a.k.a. insulin resistance).
7. The Ovaries located in the female abdomen/pelvis are best known for manufacturing and releasing estrogen and progesterone which control normal female maturation and sexual development, menstrual cycles, ovulation, pregnancy and bone density. Menopause is the naturally-occurring (or sometimes surgically-induced) loss of these hormones, sometimes necessitating replacement therapy for unmanageable symptoms.
8. The Testes (or testicles) located in the male scrotum are best known for manufacturing and releasing testosterone that controls normal male maturation and sexual development including sperm production.

The endocrine glands can also be affected by various benign and malignant tumors, which can be causes of the over- and underactivity.

Any discussion of the endocrine glands would be incomplete without some mention of the hypothalamus -- a part of the brain that manufactures and releases various "releasing' hormones that cause their target glands to release their "stimulating" hormones. For example, Thyroid Releasing Hormone makes the Pituitary's Thyroid Stimulating Hormone happen, which in turn makes the Thyroid's thyroid hormone happen. As such, the whole system often functions like a row of dominos -- after the first one falls, the rest topple over in turn. It also illustrates the complexity of Endocrinology and the importance of balance and ensuring that the various glands work in concert with one another; throwing off one often has detrimental effects on others, while correcting such imbalances can have far-reaching benefits.

With so many glands and so many effects, a working knowledge of Endocrinology is fundamental to many other medical specialties and disciplines, including but not limited to Family and Internal Medicine, Ob/GYN, General Surgery, Urology, Psychiatry, Pediatrics and Neurology.

Endocrinology and The Chester County Hospital

The endocrinologists on the Medical Staff at The Chester County Hospital are all trained to diagnose and treat the various endocrine and hormone imbalances and diseases. While the more frequently-occurring gland disorders such as Type II Diabetes and hypothyroidism are often managed by primary care physicians, these doctors must often rely on endocrinologists for help with the uncommon problems, or the common ones that are difficult to control. Sometimes both groups may need surgeons to remove glands or their tumors. As always, inter-disciplinary cooperation is essential to crafting a unique solution for each patient.

For more information about endocrinologists on the Medical Staff at The Chester County Hospital and Health System, call our Physician Referral Service at 610.738.2300 or visit theFind a Doctor section of our website.

Last Updated: 2/22/2013