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Plasma Renin Activity (measured as renin concentration)

Published: August 9, 2026Updated: August 17, 2026

This test measures the amount of renin in your blood, a hormone that helps regulate blood pressure and fluid balance.

Quick summary

["Renin activity helps doctors assess kidney function and blood pressure regulation."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
1623-8
Short code
Renin pre 600 ug Fur PO Plas-cCnc
Synonyms
Renin pre 600 ug Fur PO Plas-cCnc
Category
chemistry
Sample
plasma
Container
Lavender-top (EDTA) or Green-top (Heparin)
Units
N/A
Ref low
0
Ref high
2
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 conditions affecting fluid balance. It can also help diagnose or monitor certain hormonal imbalances or kidney-related disorders.

What Does the Test Involve?

A blood sample is drawn from a vein, usually in your arm. The sample is sent to a lab where renin levels are measured using a specialized immunoassay technique to detect and quantify the hormone.

What Does a Result Mean?

Results can vary widely based on individual health, medications, and other factors. High levels may suggest kidney issues or hormonal imbalances, while low levels could indicate conditions affecting fluid balance or kidney function. Your doctor will interpret results in the context of your overall health.

Common Reasons for Testing

This test is often used to evaluate kidney function, especially in people with hypertension (high blood pressure), chronic kidney disease, or those taking medications that affect blood pressure or fluid balance.

Reference range

NCBI: SCC <2.0 ng/mLN/A

Specimen: plasma

No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: Renin Activity plays a key role in the renin-angiotensin-aldosterone system (RAAS), which helps control blood pressure and fluid retention. Abnormal levels may indicate underlying kidney problems, hormonal disorders, or conditions requiring specific treatments like blood pressure medications.

Short name

Renin Activity

Frequently asked questions

What does a high renin level mean?
A high renin level may signal conditions such as kidney disease, excessive fluid loss, or certain hormonal imbalances. It can also occur in people with uncontrolled high blood pressure or those with conditions like primary aldosteronism.
What does a low renin level mean?
Low renin levels might suggest conditions like heart failure, liver disease, or medications that affect fluid balance. It can also occur in people with normal kidney function but under certain stress conditions.
How often should this test be repeated?
Your doctor will determine how often to repeat this test based on your symptoms, medical history, and treatment plan. Follow-up may be needed if you have ongoing kidney issues, hypertension, or other conditions affecting fluid balance.
  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 17, 2026. · Read our editorial policy