PSA is the serum prostate-specific antigen, which is the most common screening index for prostate cancer, divided into total PSA and free PSA. for male patients older than 50 years old, prostate cancer screening currently relies on the PSA index, and it is generally recommended that PSA > 3ng/mL is abnormal and should be followed closely. If the PSA is high, it is recommended that you have a prostate fingerprint to see if there are hard nodes in the prostate gland, and it is also recommended to have a prostate MRI to effectively rule out the possibility of prostate cancer.