There is very little chance of a problem from
having blood sample taken from a vein.
- You may get a small bruise at the site. You
can lower the chance of bruising by keeping pressure on the site for several
- In rare cases, the vein may become swollen after the
blood sample is taken. This problem is called phlebitis. A warm compress can be
used several times a day to treat this.
- Ongoing bleeding can be a
problem for people with bleeding disorders. Aspirin, warfarin (Coumadin), and
other blood-thinning medicines can make bleeding more likely. If you have
bleeding or clotting problems, or if you take blood-thinning medicine, tell
your doctor before your blood sample is taken.
A renin assay blood test is done to find
the cause of
high blood pressure (hypertension). The time of day
and your position (standing, sitting, or lying down) before the blood sample is
collected, your age, and the level of sodium in your blood all affect the test
The normal values listed here—called a reference range—are just a guide. These ranges vary from lab to lab, and your lab may have a different range for what's normal. Your lab report should contain the range your lab uses. Also, your doctor will evaluate your results based on your health and other factors. This means that a value that falls outside the normal values listed here may still be normal for you or your lab.
Plasma renin activity
| Adult (upright
position, normal-sodium diet)
nanograms per milliliter per hour (ng/mL/hr) or
micrograms per liter per hour (mcg/L/hr)
|Adult (lying down, normal-sodium diet)
0.2–1.6 ng/mL/hr or 0.2–1.6
|Adult (upright position,
4.2–19.8 ng/mL/hr or 4.2–19.8
|Adult (lying down, low-sodium diet)
0.4–3.2 ng/mL/hr or 0.4–3.2
Many things can affect renin test results. Your
doctor will talk with you about any abnormal results that may be related to
your symptoms and past health.
A high renin value can mean kidney
disease, blockage of an artery leading to a kidney,
cirrhosis, excessive bleeding (hemorrhage), or
malignant high blood pressure is present.
A low renin value can mean
some types of kidney disease or Conn's syndrome is present.
What Affects the Test
Reasons you may not be able to
have the test or why the results may not be helpful include:
- Eating natural black licorice in the 2 weeks
before the test.
- Taking some medicines used to treat high blood
- Taking aspirin, caffeine,
- Your position (standing,
sitting, or lying down) before the test is done or the time of day when the
blood sample is drawn, as well as recent salt intake.
- Taking very
high doses of
- Being pregnant.