What is this test?
Renin is an enzyme produced by the kidneys that helps regulate blood pressure and the balance of salt and fluid in the body.
Why might it be ordered?
- With difficult to control or abnormal blood pressure.
- To evaluate the renin-aldosterone system, usually together with aldosterone.
What sample is needed?
Venous blood is drawn into a suitable plasma tube; the sample requires proper laboratory processing.
How should you prepare?
Body position, salt intake, time of day and many medications affect the result. Follow the individual protocol and do not change medications without a doctor's instruction. Tell the laboratory about all medicines, hormone treatments, vitamins and supplements you take. Do not stop or change treatment unless your clinician tells you to. Follow any instructions about fasting and the time of collection.
How should you understand the result?
Renin is commonly assessed with aldosterone and sometimes as a ratio. A result without data on the preparation and drugs may be misleading. Your result is interpreted using the reference interval on the laboratory report and in the context of your symptoms, medical history and other test findings.
Sources and editorial status
This patient-facing text is an editorial draft. It should be approved by a laboratory physician before official publication.