The fPSA, which has a normal range of 0-1ng/mL, is the free prostate-specific antigen. fPSA cannot be examined purely for fPSA, it has to be examined together with tPSA. The general judgment is that only Tpsa is greater than 3ng/mL, which suggests an abnormality. In this case, the ratio of tPSA to fPSA is used to determine whether further testing is needed. If the tPSA is high, greater than 100ng/mL, this is a condition to consider for prostate cancer. For a general increase, it is important to be aware of the risk of prostate cancer.