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Plasma Renin Activity (measured via angiotensin I generation rate)

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

This test measures how much of the enzyme renin your body produces in 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
49331-2
Short code
Renin 2h p chal Plas-cCnc
Synonyms
Renin 2h 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 Is This Test Done?

Your doctor may order this test if you have symptoms like high blood pressure, kidney problems, or signs of fluid imbalance. It can also help diagnose conditions like primary aldosteronism or other hormonal imbalances affecting blood pressure.

What Does the Test Involve?

You’ll provide a blood sample (usually from a vein in your arm) to collect plasma. The lab then measures how much angiotensin I is produced over time when renin acts on a substrate.

What Does a Result Mean?

Results are not given in a standard numeric range because they depend on clinical context (e.g., patient age, medications, or kidney function). Your doctor will interpret the result in relation to your symptoms and other tests.

Common Conditions This Test Helps Diagnose

High renin activity may indicate conditions like renal artery stenosis (narrowed kidney arteries) or certain forms of hypertension. Low levels could suggest medications affecting renin or other hormonal disorders.

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 factors might affect my test results?
Several factors can influence renin activity, including certain medications (like beta-blockers or diuretics), kidney function, salt intake, and stress. Avoiding these factors for a few days before testing can improve accuracy.
How long does it take to get results?
Results are typically available within 1–3 business days, depending on your lab’s processing time. Your doctor will contact you once they’re ready.
Can I eat or drink before this test?
For most renin activity tests, you can eat and drink normally unless instructed otherwise. However, some labs may recommend fasting or specific dietary restrictions—always follow your doctor’s guidance.
  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