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Plasma Renin Activity (measured by renin concentration)

Published: August 9, 2026Updated: August 16, 2026

This test measures the activity level of renin, an enzyme produced by your kidneys that plays a key role in regulating blood pressure and fluid balance.

Quick summary

["Renin activity helps assess kidney function and blood pressure regulation."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
100818-4
Short code
Renin sp1 p chal Plas-mCnc
Synonyms
Renin sp1 p chal Plas-mCnc
Category
chemistry
Sample
plasma
Container
Lavender-top (EDTA) or Green-top (Heparin)
Units
N/A
Ref low
44
Ref high
147
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
84075
SNOMED
27550007
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

What Is Renin Activity Used For?

Renin activity is primarily used to evaluate how well your kidneys are managing blood pressure and fluid balance. It can help diagnose conditions like primary aldosteronism, renal artery stenosis, or certain forms of hypertension that may not respond to standard treatments.

How Is This Test Performed?

A blood sample is drawn from a vein, usually in your arm. The sample is then processed to measure renin concentration in your plasma. The test may require fasting or specific timing to ensure accurate results.

Why Might You Need This Test?

Your healthcare provider may order this test if you have symptoms like high blood pressure, unexplained fluid retention, or if you have a family history of kidney-related conditions affecting blood pressure regulation.

What Does a Result Mean?

Results are interpreted based on clinical context and other test findings. Elevated levels may indicate conditions affecting kidney function or blood pressure regulation, while lower levels could suggest other underlying issues.

Reference range

Adult: 44-147 U/LN/A

Specimen: plasma

No special preparation required. Avoid fatty meals before the test if possible.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Renin Activity (Plasma)

Frequently asked questions

Why do I need this test?
Your doctor may recommend this test to check if your kidneys are producing enough renin, which can help identify conditions like certain types of hypertension or kidney disorders that affect blood pressure.
How long does it take to get my results?
Results are typically available within 1 to 3 business days, depending on your lab’s processing time and any additional follow-up tests.
Can I eat or drink anything before this test?
Follow your doctor’s instructions regarding fasting or dietary restrictions, as some tests require specific preparation to ensure accurate results.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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