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Plasma Renin Activity (measured as angiotensin-converting enzyme activity)

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 your 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
12902-3
Short code
Renin sp4 p chal Plas-cCnc
Synonyms
Renin sp4 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 kidney artery stenosis.

What Does the Test Involve?

You’ll provide a blood sample, usually drawn from a vein in your arm. The lab will measure the amount of renin in your plasma using a specialized method.

What to Expect Before the Test

No special preparation is needed, but inform your doctor about any medications, especially those for blood pressure or heart conditions, as they may affect results.

What the Results Mean

Results help determine if your kidneys are producing enough renin or if there’s an imbalance affecting blood pressure or fluid levels. Abnormal levels may indicate underlying health issues requiring 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

How often should I expect this test?
This test is typically ordered as needed, often when symptoms or medical history suggest kidney or blood pressure issues. Your doctor will determine the timing based on your health needs.
What does it mean if my renin levels are too high or too low?
High renin levels may indicate conditions like kidney artery narrowing or certain types of hypertension. Low renin levels could suggest conditions like primary aldosteronism or other hormonal imbalances that affect fluid and electrolyte balance.
Can I take my blood pressure medication before this test?
Yes, but always follow your doctor’s instructions. Some medications may affect test results, so it’s important to discuss this with your healthcare provider before the test.
  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