Aldosterone, 24-Hour Urine — Excretion Rate
Measures the amount of aldosterone released into urine over 24 hours to help evaluate adrenal hormone function, blood pressure, and fluid balance.
["This test measures how much aldosterone your body excretes in urine over one day, which can help identify causes of high blood pressure or abnormal fluid and electrolyte balance."]
Key facts at a glance
- LOINC
- 73870-8
- Short code
- A-cortolone 24h Ur-sRate
- Synonyms
- A-cortolone 24h Ur-sRate
- Category
- liver
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- Ref low
- 20
- Ref high
- 400
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 82670
- Specimen volume
- 10 mL
- Stability
- Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
What is this test?
This test measures aldosterone, a hormone made by the adrenal glands that helps regulate sodium, potassium, fluid balance, and blood pressure. A 24-hour urine collection shows the total amount of aldosterone released by the body during a full day.
Why might I need this test?
Doctors may use this test when high blood pressure, low potassium, dizziness, fluid changes, or other signs suggest an imbalance in aldosterone. It may also be used to evaluate adrenal gland function or monitor the effects of medications that affect the renin-angiotensin-aldosterone system.
How is the test performed?
You collect all urine produced during a complete 24-hour period in a labeled container provided by the laboratory. The laboratory measures the aldosterone in the collected urine and may report the amount excreted per day, often along with other urine measurements.
How do I prepare for the test?
Follow the laboratory's collection instructions carefully, including the start and end times and any medication or dietary instructions. Do not stop prescribed medicines without medical guidance, because certain blood pressure medications and other drugs can affect the result. Tell the healthcare team if you were ill, had unusually high salt intake, or missed part of the collection.
Reference range
Premenopausal: 20-400 pg/mL; Postmenopausal: <30 pg/mLN/A
No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
24-Hour Urine Aldosterone
Frequently asked questions
Why is a 24-hour urine collection needed?
Does eating a lot of salt affect the result?
Should I stop my medications before this test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy