The prostate-specific antigen (PSA) test measures the level of a protein made by cells in the prostate gland in a man’s blood. PSA levels rise when there’s a problem with the prostate. It’s normal to have a low level of PSA. Having prostate cancer can increase it, which is why we recommend that men follow our prostate cancer screening guidelines. Men with an abnormal digital rectal exam (DRE) or a worrisome PSA test may be referred for additional testing.

However, an elevated or rising PSA level alone does not always mean that a man has prostate cancer. In fact, most men with a high PSA level don’t have prostate cancer. PSA levels increase with age and may be higher in men with a common, noncancerous condition called benign prostatic hyperplasia, or another condition called prostatitis, an inflammation of the gland. For a diagnosis of prostate cancer, we have to perform a prostate biopsy.

A high PSA level does not generally mean that a man should have a prostate biopsy. A doctor will often repeat the PSA test after a few months to determine if the level is still high and investigate whether there is a reason, other than cancer, that could explain why the PSA level is elevated.