PSA - Total
Prostate Specific Antigen (PSA) is a protein which is released into the blood by the prostate gland. Prostate cancer can raise PSA levels but a PSA test in isolation is not to be relied upon to diagnose prostate cancer, as levels can be raised in benign prostate disorders (a false positive).
There is also the potential for PSA levels to be normal despite the presence of prostate cancer, this is called a false negative.
What might a low result mean?
Small amounts of PSA in the blood are completely normal.
What might a high result mean?
When used for screening in healthy men it is more common for an elevated PSA result to be due to an innocent cause than it is for there to be prostate cancer. Approximately 75% of such positive PSA results are 'false-positives' where the elevation has an innocent cause such as a urine infection or inflammation of the prostate.