Hyperaldosteronism - primary and secondary

Alternative names
Conn’s syndrome


Primary hyperaldosteronism is a syndrome associated with increased secretion of the hormone aldosterone (see the aldosterone test) by the adrenal gland, caused by an abnormality within the gland.

In secondary hyperaldosteronism, the increased production of aldosterone by the adrenal cortex is caused by something outside the adrenal gland that mimics the primary condition.

Causes, incidence, and risk factors

Primary hyperaldosteronism used to be considered a rare condition, but some experts believe that it may be the cause of high blood pressure in 0.5% to 14% of patients. Most cases of primary hyperaldosteronism result from a benign tumor of the adrenal gland and occur in people between 30 and 50 years old.

The excess aldosterone secreted in this condition increases sodium reabsorption and potassium loss by the kidneys and results in electrolyte imbalances.

Secondary hyperaldosteronism is generally related to hypertension (high blood pressure) and swelling disorders, such as cardiac failure, cirrhosis of the liver, and nephrotic (kidney) syndrome. In these disorders, various mechanisms from the individual disease process cause the level of the hormone to be elevated.


  • High blood pressure  
  • Headache  
  • Muscle weakness  
  • Fatigue  
  • Intermittent paralysis  
  • Numbness

Signs and tests

  • Low serum potassium level  
  • Abdominal CT scan that shows adrenal mass  
  • Elevated plasma aldosterone level  
  • Elevated urinary aldosterone  
  • Low plasma renin activity  
  • ECG that shows abnormalities associated with low potassium levels

This disease may also alter the results of the following tests:

  • Urine sodium  
  • Serum sodium  
  • Urine potassium  
  • Serum magnesium test  
  • CO2


Primary hyperaldosteronism resulting from an adenoma (tumor) is usually treated surgically. Removal of adrenal tumors may control the symptoms. Even after surgery, some people have elevated blood pressure and require medication.

Dietary sodium restriction and administration of a diuretic that blocks aldosterone action (spironolactone) may control the symptoms without surgery.

In secondary hyperaldosteronism, there is no surgical intervention, but medications and diet will be included in the patient’s treatment.

Expectations (prognosis)
The prognosis for primary hyperaldosteronism is good with early diagnosis and treatment. The prognosis for secondary hyperaldosteronism will vary depending on the patient’s primary disease process.

Impotence and gynecomastia (enlarged breasts in men) may be associated with long-term medical management in men.

Calling your health care provider
Call for an appointment with your health care provider if symptoms of hyperaldosteronism develop.

Johns Hopkins patient information

Last revised: December 5, 2012
by Potos A. Aagen, M.D.

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