Quick Facts
- Sample: 24-hour urine collection
- Fasting: No fasting required
- Turnaround: 10-14 business days. May take longer based on weather, holiday, or lab delays.
What is the purpose of this test?
The Aldosterone Urine Test, 24-Hour measures the amount of aldosterone excreted in the urine over a 24-hour period. Aldosterone is a hormone released by the adrenal gland that helps the kidney control salt, water, and potassium balance. This process helps to control blood pressure and the balance of fluids and electrolytes in the blood.
The test may help evaluate adrenal gland disorders, including aldosterone-producing tumors, and can aid in identifying causes of high blood pressure or low potassium levels.
How do I interpret the results?
Aldosterone: 2.3–21.0 mcg/24 hours
- What it means: Normal aldosterone excretion. This suggests your body is producing aldosterone within the expected range for most healthy adults.
- Typical action: No further action may be needed if your results are within the reference range and you do not have symptoms. Your healthcare provider will interpret your results along with your medical history, blood pressure, sodium intake, medications, and other laboratory findings.
Aldosterone: < 2.3 mcg/24 hours
- What it means: Lower-than-expected aldosterone levels may be associated with reduced adrenal gland function, certain medications, or other hormone imbalances.
- Typical action: Your healthcare provider may recommend additional testing or further evaluation to determine the underlying cause.
Aldosterone: > 21.0 mcg/24 hours
- What it means: Higher-than-expected aldosterone levels may be associated with primary aldosteronism, secondary hyperaldosteronism, or other conditions affecting the adrenal glands or the body's regulation of blood pressure and fluid balance.
- Typical action: Your healthcare provider may recommend confirmatory testing, such as plasma aldosterone and renin testing, imaging studies, or additional evaluation to identify the cause.
Aldosterone levels are influenced by dietary sodium intake, certain medications (such as diuretics and blood pressure medications), and other factors.
Disclaimer: Reference ranges may vary by laboratory. Listed ranges are general guidelines and may differ from those used by the performing lab. Always consult your healthcare provider for interpretation.
Pre-test preparation
You must take your lab order to the laboratory to obtain the appropriate 24-hour urine collection container before beginning collection.
No fasting is required. Follow a diet containing approximately 3 grams (135 mmol) of sodium per day for at least 2 weeks, and preferably 30 days, before specimen collection.
If you are taking diuretics, antihypertensive medications, cyclic progestational agents, estrogen, or licorice, test results may not be interpretable. Consult your healthcare provider before stopping any medications.
Collect all urine over a 24-hour period using the provided container. Refrigerate the specimen or keep it in a cool place during collection. Label the container with your full name and the collection start and end dates and times, then return the specimen promptly to the laboratory.
