Conn Syndrome

National Organization for Rare Disorders, Inc.

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It is possible that the main title of the report Conn Syndrome is not the name you expected. Please check the synonyms listing to find the alternate name(s) and disorder subdivision(s) covered by this report.


  • Aldosteronism, Primary
  • Hyperaldosteronism, Primary

Disorder Subdivisions

  • None

General Discussion

Conn Syndrome is characterized by an increased level of the hormone aldosterone in the blood causing increased sodium levels in the blood. An increase in blood volume (hypervolemia), and a low potassium level (hypokalemic alkalosis) also occur. This disorder is characterized by periods of weakness, unusual sensations such as tingling and warmness, a transient paralysis, and muscle cramps. An increase in blood pressure (hypertension), excessive urination (polyuria), and excessive thirst (polydipsia) can also occur.


Conn Syndrome (Primary Hyperaldosteronism) is a rare metabolic endocrine disorder characterized by oversecretion of the hormone aldosterone. This hormone is produced by the adrenal glands. The disorder is caused by an abnormal growth (adenoma) in the cortex of the adrenal glands. Aldosterone causes salt (sodium or Na) retention and potassium (K) loss. In the kidneys, salivary and sweat glands, and in the cells of the mucous membranes in the intestines, aldosterone causes transfer of sodium in exchange for potassium and hydrogen. Aldosterone secretion is regulated by the renin-angiotensin mechanism in the kidneys and liver, and to a lesser extent by adrenocorticotropin hormone (ACTH). The sodium and water retention resulting from increased aldosterone secretion increases the blood volume and reduces renin secretion.

Increased blood levels of sodium (hypernatremia), an increase in blood volume (hypervolemia), and low potassium (hypokalemic alkalosis), can cause periods of weakness, unusual sensations such as tingling and warmness, a transient paralysis, and muscle spasms. An increase in blood pressure (hypertension), kidney disease with excessive urination (polyuria), and excessive thirst (polydipsia) can also occur. With removal of the abnormal adrenal growth, remission usually occurs.


Conn Syndrome results from excessive secretion of aldosterone, a hormone produced by the outer region of the adrenal glands (adrenal cortex). Abnormally increased levels of aldosterone (aldosteronism) disrupt the proper balance of the body's water and salt content and cause other associated abnormalities, resulting in muscle weakness, excessive urination and thirst (polyuria and polydipsia), high blood pressure (secondary hypertension), and other symptoms and findings associated with the condition. In most affected individuals, Conn Syndrome is caused by the presence of a benign tumor of the adrenal cortex (adenoma). However, in extremely rare cases, Conn Syndrome may be due to a cancerous tumor (adrenal carcinoma).

Affected Populations

Conn Syndrome appears to affect females approximately twice as often as males. Although the condition may become apparent at any age, symptom onset typically occurs in individuals who are between the ages of 30 and 50.

Standard Therapies

Treatment of Conn Syndrome often consists of surgical removal of the adrenal tumor that causes the symptoms. In some cases, treatment may include restriction of salt in the diet and administration of a medication that serves to block the action of the hormone aldosterone on the kidneys (aldosterone antagonist drug), such as spironolactone. Therapy may also include the use of other drugs that may lower blood pressure (antihypertensive agents) and promote the formation and excretion of urine while preventing further potassium depletion (potassium-sparing diuretics), such as the medications amiloride or triamterene. In rare cases in which Conn Syndrome results from the presence of a cancerous tumor, therapy may include administration of mitotane, a drug that may control or prevent the proliferation of malignant cells within the adrenal cortex (adrenocortical cytotoxic agent). In some cases, other medications may be used in the treatment of individuals with Conn Syndrome. Other treatment is symptomatic and supportive.

Investigational Therapies

Information on current clinical trials is posted on the Internet at All studies receiving U.S. government funding, and some supported by private industry, are posted on this government website.

For information about clinical trials being conducted at the National Institutes of Health (NIH) in Bethesda, MD, contact the NIH Patient Recruitment Office:

Tollfree: (800) 411-1222

TTY: (866) 411-1010




Harrison's Principles of Internal Medicine, 14th Ed.: Anthony S. Fauci et al., Eds.: McGraw-Hill Companies, Inc., 1998. Pp. 2046-48.


Aging and Aldosterone. R. Hegstad et al.; Amer Journal Med (March 1983; 74(3)). Pp. 442-48.

Pure Primary Hyperaldosteronism Due to Adrenal Cortical Carcinoma. D.J. Greathouse et al.; Amer Journal Med (June 1984; 76(6)). Pp. 1132- 36.

Primary Hyperaldosteronism Due to Adrenocortical Carcinoma. A Clinical Case Report. F. Valentini et al.; Minerva Med (Oct 13 1986; 77(39)). Pp. 1813-18.

Isolated Clinical Syndrome of Primary Aldosteronism in Four Patients with Adrenocortical Carcinoma. D. Farge et al.; Amer Journal Med (Oct 1987; 83(4)). Pp. 635-40.

Clinical Implications of Primary Aldosteronism with Resistant Hypertension. E.L. Bravo et al.; Hypertension (Feb 1988; 11(2 Pt 2). Pp. I207-11.

Occurrence of Primary Aldosteronism in a Group of Ambulatory Hypertensive Patients. A. Kreze Jr et al.; Vnitr Lek (Jan 1999; 45(1)). Pp. 17-21.

Primary Aldosteronism in General Practice (letter). P. Wilson; Lancet (Mar 20 1999; 353(9157)). Pp. 1013-14.

Primary Aldosteronism in General Practice (letter). N.N. Chan et al.; Lancet (Mar 20 1999; 353(9157)). P. 1013. Discussion: P. 1014. Comment on: Lancet (Jan 2 1999; 353(9146)). P. 40.


eMedicine - Conn Syndrome : Article by Serge A Jabbour MD


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