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Plasma Renin Activity (measured as angiotensin I generation rate)

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

This test measures how much of the enzyme renin your blood produces. 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
12904-9
Short code
Renin sp6 p chal Plas-cCnc
Synonyms
Renin sp6 p chal Plas-cCnc
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 This Test Is Done

Your doctor may order this test if they suspect conditions like kidney disease, high blood pressure (hypertension), or certain hormonal imbalances that affect how your body controls fluid and pressure. It can also help diagnose conditions like primary aldosteronism or renovascular hypertension.

What to Expect Before the Test

No special preparation is needed, but you may be asked to avoid certain medications (like some blood pressure drugs) or foods (like salt) for a short time before testing. Your doctor will provide specific instructions if applicable.

How the Test Is Performed

A blood sample is drawn from a vein, usually in your arm. The blood is then processed to measure renin activity, often by tracking the production of angiotensin I over time.

What the Results Mean

Results are interpreted based on your medical history, symptoms, and other test results. Low renin levels may indicate conditions like kidney disease or certain types of hypertension, while high levels could suggest conditions like primary aldosteronism or excessive salt intake.

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

What causes abnormal renin levels?
Abnormal renin levels can be caused by conditions affecting kidney function (e.g., chronic kidney disease), hormonal imbalances (e.g., primary aldosteronism), or certain medications that influence blood pressure or fluid balance. Lifestyle factors like high salt intake or obesity may also play a role.
How long does it take to get results?
Test results are typically available within 1 to 3 business days, depending on your lab’s processing time. Your doctor will discuss the results with you during your follow-up visit.
Can diet affect this test?
Yes, certain foods (like high-sodium or high-potassium foods) and medications (such as blood pressure drugs) may temporarily affect renin levels. Your doctor will advise you on any necessary dietary or medication adjustments before testing.
  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