PSA traveling alone is called free PSA. The free-PSA test measures the percentage of unbound PSA; the PSA test measures the total of both free and bound PSA. Prostate cancer can raise PSA levels, but so can other conditions. These include an enlarged prostate, prostatitis, and advancing age.

A total PSA test measures all the PSA, including the antigens that are bound and those that are floating freely. A free PSA test only measures the amount of PSA that is floating freely in the bloodstream, without being bound to a different protein. Both tests are used to diagnose prostate issues.

The most frequently used PSA test is the total PSA, which measures the sum of cPSA and fPSA in the blood. The PSA test may be used as a tumor marker to screen for and to monitor prostate cancer. The goal of screening is to detect prostate cancer while it is still confined to the prostate.

The normal range of free PSA measures PSA in nanograms of PSA per milliliter (ng/mL) of blood. But if you have no symptoms, the usual guidelines for total PSA levels are: Safe. Zero to 2.0 ng/mL.