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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 blood produces, which 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
17513-3
Short code
Renin 5h p chal Plas-cCnc
Synonyms
Renin 5h 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 hormonal imbalances. It can also help diagnose conditions like primary aldosteronism or kidney-related hypertension.

What Does the Test Involve?

You’ll provide a blood sample (plasma) collected in a special tube. The lab will measure how much angiotensin I (a hormone) your blood produces over time when exposed to renin.

What Does the Result Mean?

Results are interpreted based on your clinical picture, not absolute numbers. High or low renin levels may suggest kidney dysfunction, hormonal disorders, or other conditions affecting blood pressure.

Common Conditions Linked to Renin Activity

Elevated renin may indicate kidney artery stenosis, certain types of hypertension, or adrenal gland disorders. Low renin could signal conditions like heart failure, cirrhosis, or medications affecting fluid balance.

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 false high or low results?
False high results may occur if you’re dehydrated, taking certain medications (like diuretics), or have recent kidney stress. False low results can happen with medications (e.g., beta-blockers), obesity, or chronic kidney disease.
How soon will I get results?
Results typically take 1–3 business days, depending on lab processing. Your doctor will discuss them with you during your follow-up visit.
Can I eat or drink before this test?
No special diet is needed, but avoid alcohol or caffeine 24 hours before testing to avoid affecting blood pressure or hormone levels.
  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