Prostate-specific antigen (PSA) is a glycoprotein that is produced by the prostate gland, the lining of the urethra, and the bulbourethral gland. Normally, very little PSA is secreted in the blood. Increases in glandular size and tissue damage caused by benign prostatic hypertrophy, prostatitis, or prostate cancer may increase circulating PSA levels.
For men who wish to be screened for prostate cancer, the American Cancer Society recommends that healthy men of average risk consider waiting to get tested until age 50, while the American Urological Association recommends screening for men between the ages of 55 and 69 with no routine screening after age 70.
For those at high risks such as American men of African descent and men with a family history of diseases.
Avoid ejaculation for 24 hours before sample collection as it has been associated with elevated PSA levels; the sample should also be collected prior to your health practitioner performing a digital rectal exam (DRE) and prior to (or several weeks after) a prostate biopsy.
The “normal” PSA serum concentration remains a debate, however, for most laboratory readings, it should be less than 4.0 ng/mL. The prostate gland generally increases in size and produces more PSA with increasing age. So it is normal to have lower levels in young men and higher levels in older men.