Health Encyclopedia

Adrenal glands

Definition

The adrenal glands are two small triangle-shaped glands in the upper abdomen. One gland is located on top of each kidney.

Information

Each adrenal gland is about the size of the top part of the thumb. The outer part of the gland is called the cortex. It produces steroid hormones such as cortisol, aldosterone, and hormones that can be changed into testosterone. The inner part of the gland is called the medulla. It produces epinephrine and norepinephrine. These hormones are also called adrenaline and noradrenaline.

When the glands produce more or less hormones than normal, you can become sick. This might happen at birth or later in life.

The adrenal glands can be affected by many diseases, such as autoimmune disorders, infections, tumors, and bleeding. Some are permanent and some go away over time. Medicines can also affect the adrenal glands.

The pituitary, a small gland at the bottom of the brain, releases a hormone called ACTH that stimulates the adrenal cortex to make its hormones. Pituitary diseases can lead to problems with adrenal function.

Conditions related to adrenal gland problems include:

Addison disease, also called adrenal insufficiency -- an autoimmune disorder that causes the adrenal glands to not produce enough hormones
Congenital adrenal hyperplasia -- disorder in which the adrenal glands lack an enzyme needed to make certain hormones
Cushing syndrome -- disorder that occurs when the body has a high level of the hormone cortisol
Diabetes mellitus (high blood sugar) caused by the adrenal gland making too much cortisol
Glucocorticoid medicines such as prednisone, methylprednisolone, dexamethasone, and hydrocortisone
Excessive or unwanted hair in women (hirsutism)
Hump behind shoulders (dorsocervical fat pad)
Hypoglycemia -- low blood sugar
Primary aldosteronism (Conn syndrome) -- disorder in which the adrenal gland releases too much of the hormone aldosterone
Massive bilateral adrenal hemorrhage (Waterhouse-Friderichsen syndrome) -- failure of adrenal glands to function as a result of bleeding into the gland, usually associated with severe infection, called sepsis

References

Friedman TC. Adrenal gland. In: Wing EJ, Schiffman FJ, eds. Cecil Essentials of Medicine. 10th ed. Philadelphia, PA: Elsevier; 2022:chap 66.

Newell-Price JDC, Auchus RJ. The adrenal cortex. In: Melmed S, Auchus, RJ, Goldfine AB, Koenig RJ, Rosen CJ, eds. Williams Textbook of Endocrinology. 14th ed. Philadelphia, PA: Elsevier; 2020:chap 15.

Standring S. Suprarenal (adrenal) gland. In: Standring S, ed. Gray's Anatomy. 42nd ed. Philadelphia, PA: Elsevier; 2021:chap 70.

Review Date:4/29/2022
Reviewed By:Sandeep K. Dhaliwal, MD, board-certified in Diabetes, Endocrinology, and Metabolism, Springfield, VA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997-A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

The Agency for Health Care Administration (Agency) and this website do not claim the information on, or referred to by, this site is error free. This site may include links to websites of other government agencies or private groups. Our Agency and this website do not control such sites and are not responsible for their content. Reference to or links to any other group, product, service, or information does not mean our Agency or this website approves of that group, product, service, or information.

Additionally, while health information provided through this website may be a valuable resource for the public, it is not designed to offer medical advice. Talk with your doctor about medical care questions you may have.