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Plasma Renin Activity (measured as renin concentration)

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

This test measures the level of renin in your blood plasma. Renin is 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
100820-0
Short code
Renin sp3 p chal Plas-mCnc
Synonyms
Renin sp3 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

Why Is This Test Done?

Your doctor may order this test if they suspect conditions like hypertension (high blood pressure), kidney disease, or other disorders affecting your kidneys’ ability to control fluid and salt balance. It can also help evaluate whether certain medications are affecting your blood pressure or kidney function.

What Does the Test Involve?

A blood sample is drawn from a vein, usually in your arm. The blood is then processed to separate plasma, which is sent to a lab for analysis. The test measures renin concentration, which can be influenced by factors like diet, medications, and kidney health.

What Might Affect Results?

Several factors can influence renin levels, including medications (such as diuretics or beta-blockers), kidney function, salt intake, and hormonal imbalances. Stress, dehydration, or recent physical activity can also temporarily affect results.

What Are Common Uses?

This test is often used alongside other blood pressure or kidney-related tests to diagnose or monitor conditions like primary aldosteronism, renal artery stenosis, or conditions affecting the renin-angiotensin system.

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.

Clinical Significance

Short name

Renin Activity

Frequently asked questions

What questions might you have?
This test alone may not provide a definitive diagnosis, but it can help guide further testing or treatment plans. High renin levels might indicate overactivity of the renin-angiotensin system, while low levels could suggest kidney dysfunction or other underlying issues.
How often should I expect follow-up tests?
Follow-up testing depends on your doctor’s recommendations. If your results are abnormal, they may recommend additional tests (like blood pressure monitoring, kidney function tests, or imaging) to explore the cause. Your doctor will discuss this with you during your visit.
Can diet or medications affect this test?
Yes, certain medications (such as ACE inhibitors or diuretics) can lower renin levels, while others (like beta-blockers) may raise them. Avoiding salt-heavy foods or certain supplements for a few days before testing may help stabilize results. Always follow your doctor’s specific instructions.
  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