PSA screening is a tumor marker for screening prostate cancer. PSA test is performed through blood tests for screening, the upper limit of normal value of PSA calibration is 4ng/ml, if the blood test item of PSA is abnormally increased, it is necessary to consult a doctor in time to improve the relevant examination. PSA full name prostate specific antigen, is a protein, mainly in the human prostate and semen, mainly secreted by the prostate cells. Generally, the amount of PSA in human blood is limited. If PSA is elevated, it means there is an abnormality in the prostate gland, and you need to look for the factors that cause it to be elevated. PSA is not prostate cancer-specific antigen, if the test to PSA elevated, not absolutely is suffering from prostate cancer, prostatitis via rectal fingerprinting, prostate massage and puncture and other such factors can cause different degrees of PSA elevation in the blood, prostate cancer in general belongs to the older men’s disease, the young men are less likely to carry out the examination. PSA test is mainly used for screening and diagnosis of prostate cancer, you should not judge or diagnose on your own based on the result of one test, you should consult the doctor in time, the doctor will analyze and diagnose according to the specific situation.