Conn's Syndrome

A hypertensive disorder resulting from excess production of aldosterone by the adrenal gland.

Causes and Incidence 

Most cases are caused by an adenoma of the adrenal gland. Other causes are adrenal nodular hyperplasia and adrenal carcinoma. Only 0.5% to 2% of those with hypertension are affected. The condition is three times more likely to affect women; the typical age ranges from 30 to 50 years.

Disease Process 

Excess production of aldosterone leads to hypernatremia, hypervolemia, and hypokalemic alkalosis. Mild to severe arterial hypertension occurs because of the increased volume and arteriolar sodium levels. Hypokalemia results from increased renal excretion of potassium, and metabolic alkalosis occurs because of an increase in hydrogen ion secretion. Over time this leads to transient paralysis and tetany.

Symptoms 

In many cases the only manifestation is a mild to moderate hypertension. Other signs and symptoms include episodic weakness, fatigue, paresthesia, polyuria, polydipsia, and nocturia. Glycosuria, hyperglycemia, and personality disturbances are occasionally manifested.

Potential Complications 

Marked alkalosis with transient paralysis, tetany, and positive Chvostek's and Trousseau's signs.
 

Diagnostic Tests 

Plasma renin activity 
Decreased (measured after restricted sodium/diuretic therapy)

Aldosterone levels
Increased (measured after  sodium loading)

Blood chemistry
Normal/increased sodium, decreased potassium

Computed tomography scan
To detect presence of adenoma

Blood pressure
Elevated

Edema
Absent
 

Treatments 

Surgery
Adrenalectomy

Drugs
Spironolactone (Aldactone)

General 
Low-sodium diet; instruction about medication, diet, and surgery.