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Plasma Renin Activity (measured via renin substrate conversion)

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

This test measures how much renin your body produces in the plasma. Renin 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
100819-2
Short code
Renin sp2 p chal Plas-mCnc
Synonyms
Renin sp2 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 Testing For?

Renin activity testing helps evaluate whether your kidneys are producing enough renin—a hormone that influences blood pressure and fluid balance. It may be used to diagnose conditions like primary aldosteronism, kidney disease, or certain forms of hypertension.

How Is This Test Performed?

A blood sample is drawn from a vein, typically in your arm. The sample is sent to a lab where it’s analyzed to measure renin activity levels. This process usually takes a few days for results.

Why Might Your Doctor Order This Test?

Your doctor may recommend this test if you have symptoms like unexplained high blood pressure, frequent urination, or signs of kidney problems. It can also help determine if certain medications (like ACE inhibitors) are affecting your renin levels.

What Does the Test Result Mean?

Results are interpreted by your healthcare provider based on your overall health and symptoms. High or low renin levels may indicate specific medical conditions that require further evaluation.

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

Frequently asked questions

Why do I need this test if I don’t have symptoms?
Your doctor may order this test as part of a broader evaluation for suspected conditions like hypertension, kidney disease, or hormonal disorders—even if you’re asymptomatic. It helps identify subtle imbalances that could affect long-term health.
How long does it take to get results?
Results typically take 3–5 business days, depending on lab processing times. Your doctor will contact you once they’re ready.
Can I eat or drink anything before this test?
No special preparation is needed, but follow your doctor’s instructions if they specify dietary restrictions (e.g., low-sodium diets for kidney-related tests).
  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