Renin

Alternative names:

plasma renin activity; PRA; random plasma renin

What the risks are:

• excessive bleeding
• fainting or feeling lightheaded
• hematoma (blood accumulating under the skin)
• infection (a slight risk any time the skin is broken)
• multiple punctures to locate veins

Special considerations:

Renin measurements are affected by pregnancy, salt intake, time of day, and a standing vs. prone position.

Drugs that can affect renin measurements include antihypertensives, diuretics, estrogens, oral contraceptives and vasodilators.

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.