The upper limit of normal value for prostate PSA calibration is 4ng/ml, but the value may vary due to different means of detection, so you can refer to the upper limit of normal value labeled on the lab sheet.
PSA is the abbreviation of prostate-specific antigen, which can be synthesized in both normal and cancer-like epithelial cells. Under normal circumstances, PSA is secreted into the semen and plays a normal physiological role in the division of the seminal vesicle package and the liquefaction of semen, and only a very low level of PSA exists in the bloodstream, so the upper limit of its general normal value is 4ng/ml.
If the test found that the increase in serum PSA concentration can indicate pathological changes or trauma to the prostate, may be related to prostatitis, benign prostatic hyperplasia or prostate cancer, at this time can be recommended by the physician to do further testing to clarify or to detect the specific cause of the disease.