Navigate Up

Cancer Center - A-Z Index

#
Q
Y

Print This Page

Renin blood test

The renin test measures the level of renin in blood.

Alternative Names

Plasma renin activity; Random plasma renin; PRA

How the Test is Performed

A blood sample is needed.

How to prepare for the test

Certain medicines may affect the results of this test. Your doctor will tell you if you need to stop taking any medicines. Do not stop any medicine before talking to your doctor.

Medicines that can affect renin measurements include:

  • Birth control pills
  • Blood pressure drugs
  • Medicines that enlarge blood vessels (vasodilators); these are usually used to treat high blood pressure or heart failure
  • Water pills (diuretics)

Eat a normal, balanced diet with moderate sodium content (no more than 3 grams a day) for 3 days before the test.

Be aware that renin level can be affected by pregnancy as well as time of day and body position when blood is drawn.

How the Test will Feel

When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging sensation. Afterward, there may be some throbbing or a slight bruise. These soon go away.

Why the Test is Performed

Renin is a protein (enzyme ) released by special kidney cells when you have a decreased salt (sodium) level or low blood volume.

If you have high blood pressure , your doctor may order a renin and aldosterone test to see if you are sensitive to salt.

Test results can help guide your doctor in choosing the correct medicine. Salt-sensitive patients with high blood pressure associated with low renin levels respond well to diuretic medicines.

Normal Results

Normal values range from 0.2 to 3.3 ng/mL/hour.

Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your doctor about the meaning of your specific test results.

What Abnormal Results Mean

High levels of renin may be due to:

Low renin levels may be due to:

  • Adrenal glands releasing too much aldosterone hormone (hyperaldosteronism)
  • High blood pressure that is salt-sensitive
  • Treatment with antidiuretic hormone (ADH)
  • Treatment with steroid medicines that causes the body to retain salt

Risks

Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.

Other risks associated with having blood drawn are slight but may include:

  • Excessive bleeding
  • Fainting or feeling lightheaded
  • Hematoma (blood accumulating under the skin)
  • Infection (a slight risk any time the skin is broken)

References

Blumenfeld JD, Liu F, Laragh JR. Primary and secondary hypertension. In: Taal MW, Chertow GM, Marsden PA, Skorecki K, Yu ASL, Brenner BM, eds. Brenner & Rector's The Kidney. 9th ed. Philadelphia, Pa: Elsevier Saunders; 2011:chap 46.

Gruber HA, Farag AF. Evaluation of endocrine function. In: McPherson RA, Pincus MR, eds. Henry’s Clinical Diagnosis and Management by Laboratory Methods. 22nd ed. Philadelphia, Pa: Elsevier Saunders; 2011:chap 24.

Oh MS. Evaluation of renal function, water electrolytes, and acid-base balance. In: McPherson RA, Pincus MR, eds. Henry’s Clinical Diagnosis and Management by Laboratory Methods. 22nd ed. Philadelphia, Pa: Elsevier Saunders; 2011:chap 14.

Updated: 8/25/2013

David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial team.


©  UPMC | Affiliated with the University of Pittsburgh Schools of the Health Sciences
Supplemental content provided by A.D.A.M. Health Solutions. All rights reserved.

For help in finding a doctor or health service that suits your needs, call the UPMC Referral Service at 412-647-UPMC (8762) or 1-800-533-UPMC (8762). Select option 1.

UPMC is an equal opportunity employer. UPMC policy prohibits discrimination or harassment on the basis of race, color, religion, ancestry, national origin, age, sex, genetics, sexual orientation, marital status, familial status, disability, veteran status, or any other legally protected group status. Further, UPMC will continue to support and promote equal employment opportunity, human dignity, and racial, ethnic, and cultural diversity. This policy applies to admissions, employment, and access to and treatment in UPMC programs and activities. This commitment is made by UPMC in accordance with federal, state, and/or local laws and regulations.

Medical information made available on UPMC.com is not intended to be used as a substitute for professional medical advice, diagnosis, or treatment. You should not rely entirely on this information for your health care needs. Ask your own doctor or health care provider any specific medical questions that you have. Further, UPMC.com is not a tool to be used in the case of an emergency. If an emergency arises, you should seek appropriate emergency medical services.

For UPMC Mercy Patients: As a Catholic hospital, UPMC Mercy abides by the Ethical and Religious Directives for Catholic Health Care Services, as determined by the United States Conference of Catholic Bishops. As such, UPMC Mercy neither endorses nor provides medical practices and/or procedures that contradict the moral teachings of the Roman Catholic Church.

© UPMC
Pittsburgh, PA, USA UPMC.com