Prostate-Specific Antigen (PSA) Test

Prostate-specific antigen (PSA) is a substance released into a man's blood by his prostate gland. A PSA test measures the amount of prostate-specific antigen in the blood.

Low amounts of PSA may be found in the blood of healthy men. The amount of PSA in the blood normally increases as a man's prostate enlarges with age. It is also increased by ejaculation, inflammation of the prostate gland (prostatitis), and by prostate cancer.

Last Revised: September 12, 2012

Author: Healthwise Staff

Medical Review: E. Gregory Thompson, MD - Internal Medicine & Christopher G. Wood, MD, FACS - Urology, Oncology

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