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.
How this information was developed to help you make better health decisions.