ALDOSTERONE - SERUM

Aldosterone - Serum is a specialized blood test used to measure the concentration of aldosterone in serum. Aldosterone is a steroid hormone produced by the adrenal glands, which are located above the kidneys. It helps regulate blood pressure, blood volume, sodium retention, potassium excretion, and the body's overall fluid balance.

This test is frequently evaluated together with a renin test because the relationship between aldosterone and renin provides more clinically useful information than either measurement alone. The calculated aldosterone-to-renin ratio may support screening for primary aldosteronism in appropriately selected patients.

Benefits of the Test

• Measures the concentration of aldosterone in serum.
• Supports evaluation of difficult-to-control high blood pressure.
• Helps investigate hypertension associated with low potassium.
• Assists in screening for primary aldosteronism.
• Supports evaluation of suspected adrenal gland disorders.
• Helps investigate abnormal sodium and potassium levels.
• May be combined with renin testing for improved interpretation.
• Supports further diagnostic and treatment planning.

Why Doctors Recommend This Test

Doctors may recommend this test for individuals with resistant hypertension, high blood pressure developing at a young age, hypertension associated with low potassium, an adrenal mass, unexplained muscle weakness, excessive thirst, frequent urination, or suspected overproduction or underproduction of aldosterone. It may also be used when evaluating possible adrenal insufficiency or disorders affecting fluid and electrolyte balance.

Preparation Before Test

• Testing may be recommended in the morning because aldosterone levels can vary during the day.
• The doctor or laboratory may specify whether the sample should be collected after sitting, standing, or resting for a defined period.
• Maintain your usual sodium intake unless your doctor provides different instructions.
• Inform your doctor about all prescription medicines, supplements, diuretics, blood-pressure medicines, steroids, hormonal medicines, and potassium products.
• Do not discontinue any medicine or change your salt intake without medical advice.
• Low potassium may need to be corrected before certain aldosterone-renin evaluations under medical supervision.
• Follow all posture, timing, diet, and collection instructions provided by the laboratory.

Normal Reporting Time

The reporting time for the Aldosterone - Serum test depends on sample receipt, testing schedules, analytical methodology, quality review, and whether the sample is processed locally or referred to a specialized laboratory. Results are generally completed within several working days. Please confirm the expected turnaround time with Focus Diagnostics during sample collection.

Who Should Take This Test?

This test may be recommended for:

• Patients with resistant or difficult-to-control hypertension.
• Individuals with high blood pressure and low potassium levels.
• People who develop hypertension at a relatively young age.
• Patients with a suspected adrenal gland disorder.
• Individuals with an adrenal mass discovered during imaging.
• Patients with unexplained weakness, thirst, or frequent urination.
• People undergoing aldosterone-to-renin ratio evaluation.
• Patients being assessed for excessive or deficient aldosterone production.

Detailed Information

Aldosterone is part of the renin-angiotensin-aldosterone system, which helps maintain blood pressure and fluid balance. When blood pressure, sodium concentration, or circulating blood volume decreases, the kidneys release renin. This initiates a sequence of reactions that stimulates the adrenal glands to produce aldosterone.

Aldosterone acts primarily on the kidneys. It promotes sodium and water retention while increasing potassium excretion. These actions help increase circulating blood volume and maintain blood pressure. Excessive or insufficient aldosterone production can therefore affect blood pressure and electrolyte levels.

Elevated aldosterone levels may occur in primary aldosteronism, also known as primary hyperaldosteronism or Conn syndrome. This condition may result from an aldosterone-producing adrenal adenoma or excessive activity in both adrenal glands. It commonly causes hypertension and may cause low potassium, although potassium can remain normal in some patients.

Secondary hyperaldosteronism occurs when increased aldosterone production is driven by elevated renin activity. It may be associated with reduced blood flow to the kidneys, certain heart or liver conditions, fluid loss, or other disorders affecting circulating blood volume.

Low aldosterone levels may be seen in certain forms of adrenal insufficiency, reduced renin production, kidney-related disorders, or conditions affecting adrenal hormone synthesis. Additional hormone and electrolyte tests are usually required to determine the cause.

A serum aldosterone result should not be interpreted using a single universal range. Reference intervals can vary according to the analytical method, collection time, sodium intake, potassium level, age, posture before collection, and medicines being taken.

Aldosterone is commonly measured together with renin to calculate an aldosterone-to-renin ratio. An elevated ratio may support possible primary aldosteronism, but it is a screening finding rather than a final diagnosis. Confirmatory testing and adrenal imaging may be recommended depending on the clinical situation.

Several medicines can influence aldosterone, renin, potassium, or blood pressure and may affect test interpretation. Patients must not stop prescribed medication independently. The treating doctor should determine whether any change is necessary and medically safe.

Results should be interpreted alongside blood pressure measurements, serum potassium and sodium, kidney function, renin results, symptoms, medication history, and clinical examination.

At Focus Diagnostics, Aldosterone - Serum testing is performed using validated laboratory methodologies and established quality-control procedures to provide accurate and clinically meaningful results.