Prostate specific antigen (PSA) is a protein made by the prostate. Prostate is a walnut-sized gland in men that makes a fluid for semen.

Most PSA is released into semen. Some of it is released into the blood. If there is a problem with the prostate, the PSA level in the blood can become elevated.

Anatomy of the Prostate
Anatomy of the Prostate Gland
Copyright © Nucleus Medical Media, Inc.

The PSA test is used to:

  • Monitor treatment effectiveness for prostate cancer
  • Help determine if cancer has returned in men who have already been treated for prostate cancer
  • Test for other conditions, like prostatitis, or benign prostatic hyperplasia

The PSA test may also be used as a screening tool for prostate cancer. However, this use is controversial. Talk to your doctor about the risks and benefits of the PSA test, and your personal risk factors for prostate cancer.