Adrenal Glands Health Article

Role in human health

Thus, the adrenal glands play a significant role in mental and physical health. Not only are the adrenal glands vital for maintaining a proper balance of sodium and potassium, they mediate the body's response to stress, both short-term and long-term. In response to immediate stress, the adrenal glands produce epinephrine, norepinephrine, and the hormone cortisol. The body is prepared for flight or fight, and energy is made available for instant use. In the long term, the adrenal glands may have a negative impact on human health. Prolonged stress can produce undesirable changes in the body that range from immune system depression to fertility complications.

Addison's disease

Addison's disease arises from a hypoactive adrenal cortex. The adrenal cortex fails to produce adequate amounts of the glucocorticoid cortisol, and sometimes the mineralcorticoid aldosterone. A lack of aldosterone causes the kidneys to excrete excess sodium and water while retaining potassium. This can lead to hyperkalemia (high levels of potassium), hypovolemia (low blood volume), and hypotension (low blood pressure). Hyperkalemia may cause fatal heart arrhythmias, and (severe) hypovolemia can lead to shock and kidney failure. Common symptoms include frequent urination, dehydration, fatigue, dizziness, skin discoloration, nausea, vomiting, weakness, and cold intolerance. Treatment includes oral or intravenous glucocorticoids such as prednisone, and, if necessary, administration of the oral mineralcorticoid fludrocortisone acetate to replace aldosterone. The cause of Addison's disease is not known, but in 80% of the cases there is a wasting or atrophy of the adrenal cortex.

Primary aldosteronism

Conn's syndrome is also known as primary aldosteronism. In this disease, too much of the mineralcorticoid, aldosterone, is made by the adrenal glands. The increased levels of aldosterone cause excessive potassium excretion while promoting excessive sodium and water retention. This leads to hypertension (high blood pressure) and hypokalemia (low serum potassium). Hypokalemia is an important diagnostic clue in the process of differentiating primary aldosteronism from other similar disorders. In some cases, Conn's syndrome is due to an adrenal tumor, in which case it may be surgically removed. In other cases, the diuretic drugs, spironalactone or amiloride, are given to block the effects of aldosterone.

Cushing's syndrome

The adrenal cortex is overactive in Cushing's syndrome. The adrenal cortex overproduces glucocorticoids, which can lead to high blood sugar levels and high blood pressure. Symptoms include obesity, muscle wasting, fatigue, irritability, excessive hair growth in women, irregular menstrual cycles, and decreased male fertility. A tumor of the adrenal gland, or an overproduction of ACTH by the pituitary, may cause Cushing's syndrome. Treatment may include chemotherapy or hormone-inhibiting medications.

Pheochromocytoma

Pheochromocytomas are tumors of the adrenal glands that secrete large quantities of norepinephrine and epinephrine. The most common symptom is extremely high blood pressure. Treatment is usually surgical removal of the tumor.

KEY TERMS

Adrenal cortex—Outer layer of the adrenal gland that produces steroid hormones.

Adrenal medulla—Inner layer of the adrenal gland that releases adrenaline.

Androgens—Male sex hormones.

Hyperkalemia—An abnormally high level of potassium in the blood.

Hypokalemia—An abnormally low level of potassium in the blood.

Hypovolemia—An abnormally low volume of blood.

Glucocorticoid—A steroid hormone, like cortisol, that affects fat, carbohydrate, and protein levels in the blood as well as regulating the immune response.

Mineralcorticoid—A steroid hormone, like aldosterone, that regulates the excretion of salt, potassium, and water.

BOOKS

Guyton A.C. and J.E. Hall. Medical Physiology, 10th edition, Philadelphia, PA: W.B. Saunders Company, 2000.

Guyton A.C. Medical Physiology. 8th edition. Philadelphia, PA: W.B. Saunders Company, 1991.

PERIODICALS

Hostetter T.H., Rosenber M.E., Ibrahim H.N., and Juknevicius I. "Aldosterone in renal disease." Current Opinion in Nephrology Hypertension (10 January 2001): 105-110.

ORGANIZATIONS

National Adrenal Diseases Foundation. 505 Northern Blvd, Great Neck, NY 11021. (516) 487-4992. <http://medhlp.netusa.net/nadf/>.

Susan M Mockus, Ph.D.