Reasons for low F-PSA and T-PSA ratios may include benign prostate disease (e.g., benign prostatic hyperplasia, acute prostatitis), prostate cancer, and others. F-PSA is the free prostate-specific antigen and T-PSA is the total prostate-specific antigen, and the ratio of the two is an indicator for distinguishing prostate cancer from benign prostate diseases. 1. Benign prostate disease: when T-PSA is more than 4ng/ml and less than 10ng/ml, and the ratio of F-PSA/T-PSA is more than 0.25, it suggests benign prostate disease, such as benign prostatic hyperplasia, acute prostatitis, etc., and regular review is needed. 2. Prostate cancer: when the T-PSA is more than 4ng/ml and less than 10ng/ml, and the F-PSA/T-PSA ratio is less than 0.15, the possibility of prostate cancer is relatively large, and then prostate puncture is needed to clarify whether there is prostate cancer. Low T-PSA and F-PSA ratio alone cannot determine the cause accurately, but also need to be combined with the characteristics of the medical history, other test results to make accurate judgment, it is recommended to clarify the cause of the disease under the guidance of the doctor.