Prostate Specific Antigen is made by prostate cells and is released into the bloodstream. Large prostates have more PSA, so a rise in PSA means that the gland is enlarging rapidly, which can be a sign of cancer or is irritated by infection. Free PSA is made by a normal prostate, while bound PSA is made primarily by prostate cancer cells. This rule usually holds for every situation except infection. If you have an elevated PSA blood test, your doctor will check your prostate and order a sonogram to see if you have a nodule that may be a sign of cancer.
Most urologists recommend a biopsy done in their offices.
If your PSA is low, you may have difficulty ejaculating and fathering a child. A normal ejaculate clots and traps sperm. Prostate-specific antigen, a serine protease, facilitates human prostate cancer cell invasion. FI Rodriguezrubio, JE Robles, A Gonzalez, J Arocena, G Sanz, F Diezcaballero, A Martinmarquina, JM Berian. Journal of Urology.