Serum or Plasma Free Aldosterone Concentration
This test measures the amount of aldosterone, a hormone that helps regulate blood pressure and fluid balance, in your blood. It’s often used to diagnose conditions like primary aldosteronism.
["Aldosterone helps control blood pressure and fluid balance; this test checks your free hormone levels in blood."]
Key facts at a glance
- LOINC
- 53517-9
- Short code
- RBC # Dial fld Manual
- Synonyms
- RBC # Dial fld Manual
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 4.2
- Ref high
- 5.9
- Critical range
- 2 N/A – 7 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- manual-count
- CPT
- 85041
- SNOMED
- 900000000000003001
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why This Test Might Be Ordered
Your doctor may recommend this test if you have symptoms like high blood pressure, frequent urination, or unexplained low potassium levels. It’s also used to evaluate conditions such as hyperaldosteronism or adrenal gland disorders.
What to Expect Before the Test
No special preparation is usually needed, but you may be asked to avoid certain medications (like some blood pressure drugs) for a few days before testing. Your doctor will provide specific instructions if applicable.
How the Test Works
A blood sample is drawn from a vein, typically in your arm. The sample is then sent to a lab to measure free aldosterone levels using a sensitive immunoassay method.
What the Results Mean
Results help determine if your aldosterone levels are too high or too low, which can guide treatment for conditions like hypertension or adrenal disorders. Your doctor will interpret the results in the context of your overall health.
Reference range
Adult males: 4.2-5.9; Females: 3.8-5.1 x 10^12/LN/A
No special preparation required. Stay well hydrated.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Elevated aldosterone levels may indicate primary aldosteronism, a condition causing high blood pressure and low potassium. Low levels could suggest adrenal insufficiency or other hormonal imbalances. This test is critical for diagnosing and managing these conditions to prevent complications like heart disease or kidney problems.
Short name
Free Aldosterone
Frequently asked questions
What causes abnormal aldosterone levels?
How long does it take to get results?
Can I eat or drink 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 17, 2026. · Read our editorial policy