A prostate-specific antigen (PSA) test measures the level of PSA in your blood. The prostate

is a small gland that is part of a man's reproductive system. It is located below the bladder

and makes a fluid that is part of semen. PSA is a substance made by the prostate. Men

normally have low PSA levels in their blood. A high PSA level may be a sign of prostate

cancer, the most common non-skin cancer affecting American men. But high PSA levels can

also mean noncancerous prostate conditions, such as infection or benign prostatic

hyperplasia a noncancerous enlargement of the prostate.