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Plasma Renin Activity (Renal Function Screening)

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

This test measures how actively your kidneys produce an enzyme called renin, which plays a key role in regulating blood pressure and fluid balance. It’s often checked when doctors suspect conditions like high blood pressure, kidney disease, or hormonal imbalances.

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
12906-4
Short code
Renin sp8 p chal Plas-cCnc
Synonyms
Renin sp8 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

What Does This Test Measure?

Renin is an enzyme released by your kidneys in response to low blood pressure or fluid levels. This test measures its activity in your plasma, helping doctors understand how well your kidneys are managing these processes.

Why Might Your Doctor Order This Test?

Your doctor may recommend this test if you have symptoms like high blood pressure, frequent urination, swelling, or if they suspect conditions such as primary aldosteronism, kidney disease, or certain hormonal disorders.

How Is the Test Performed?

A blood sample is taken from a vein in your arm. The sample is then sent to a lab to measure renin activity using specialized techniques, such as immunoassay or enzymatic methods.

What Are Common Uses?

This test is commonly used to diagnose or monitor conditions affecting blood pressure regulation, kidney function, or hormonal imbalances. It can also help guide treatment plans for conditions like hypertension or kidney disease.

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

Plasma Renin Activity

Frequently asked questions

What Does a High or Low Result Mean?
A high renin level may signal conditions like kidney disease, certain types of hypertension, or hormonal imbalances. A low level might suggest other factors, such as medications, kidney dysfunction, or conditions affecting fluid balance.
How Long Does It Take to Get Results?
Results are typically available within 1 to 3 business days, depending on your lab’s processing time.
Can I Take Anything Special Before This Test?
Follow your doctor’s instructions, but generally, you may eat and drink normally unless advised otherwise. Some tests may require fasting or specific dietary restrictions, so check with your healthcare provider.
  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