A normal prostate-specific antigen ratio should be >0.18. Prostate-specific antigen is a substance in the male body that originates from the epithelial cells of the prostate gland and is found in very small amounts in normal individuals. When the ratio of free prostate-specific antigen to total prostate-specific antigen is found to be <0.18 during a physical examination, it suggests that the patient may have prostate cancer. The higher the value of prostate-specific antigen and the lower the value of prostate-specific antigen ratio, the higher the possibility of diagnosing prostate cancer, but this index has limitations, and the value of prostate-specific antigen ratio only has reference value if the value of total prostate-specific antigen is 4~10ng/mL. To diagnose prostate cancer, it is necessary to combine with other tests, such as prostate ultrasound, etc., and puncture biopsy is the gold standard for diagnosing prostate cancer. When the lab indicators are abnormal, it is necessary to actively consult the doctor and follow the doctor's instructions for reasonable treatment.