The adrenal glands are two triangle-shaped glands. One gland is located on top of each kidney.
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 converted to testosterone. The inner part of the gland is called the medulla. It produces epinephrine and norepinephrine, which are also called adrenaline and noradrenaline.
When the glands produce more or less hormones than your body needs, you can become sick. Sometimes this happens right at birth. Sometimes it develops later in life.
The adrenal glands can be affected by many diseases, such as autoimmune disorders, infections, tumors, and bleeding.
Stewart PM, Krone NP. The adrenal cortex. In: Melmed S, Polonsky KS, Larsen PR, Kronenberg HM, eds.Williams Textbook of Endocrinology.
Update Date 8/5/2014
Updated by: Brent Wisse, MD, Associate Professor of Medicine, Division of Metabolism, Endocrinology & Nutrition, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.