Why this test?
This study is intended for the diagnosis of hyperaldosteronism, adrenal tumors, differential diagnosis of hypertension.
When is it prescribed?
This examination is recommended for diagnosing adrenal tumors and determining the causes of hypertension.
Aldosterone is a steroid hormone synthesized from cholesterol in the cells of the glomerular layer of the adrenal cortex. This is the main and powerful mineralocorticoid. It is metabolized in the liver and kidneys, causes an increase in the reabsorption of sodium and chlorine in the renal tubules. As a result, there is sodium and chlorine retention in the body, a decrease in fluid excretion with urine, and at the same time there is an increase in potassium excretion. Aldosterone is involved in the regulation of electrolyte balance, maintenance of blood volume and blood pressure.
Normal secretion of aldosterone depends on many factors — activity of the renin-angiotensin system, potassium content (hyperkalemia stimulates, and hypokalemia suppresses, aldosterone production), ACTH (a short-term increase in aldosterone secretion under physiological conditions is not the main regulatory factor). Excess aldosterone causes hypokalemia, metabolic alkalosis, marked retention of sodium and increased excretion of potassium with urine, which is clinically manifested by arterial hypertension, muscle weakness, convulsions and paresthesias, arrhythmias. In primary hyperaldosteronism (Conn's syndrome), there is an autonomous increase in aldosterone secretion, the cause of which is most often an adenoma of the glomerular zone of the adrenal cortex (up to 62% of all observations). Secondary hyperaldosteronism is associated with congestive heart failure, cirrhosis of the liver with the formation of ascites, certain kidney diseases, excess potassium, low-sodium diet, toxicosis of pregnant women, renal artery stenosis (2-3% of all cases of arterial hypertension). Primary hyperaldosteronism is characterized by an increase in aldosterone level combined with low plasma renin activity, secondary hyperaldosteronism is characterized by an increase in aldosterone concentration combined with high plasma renin activity.