In healthy men, the PSA level is usually between 0-4 ng (nanograms per milliliter of blood). It often increases in old age, even without a disease, so that in older men more often values are found just under 4 ng.
But even if the PSA value is above, that does not mean anything bad. As explained in the other questions on this topic, PSA alone is not a reliable marker for the presence of cancer. Elevated levels may also occur without cancer, for example, in benign prostate enlargement. And low PSA levels do not preclude a tumor disease.
Therefore, the PSA test has its significance especially in conjunction with other diagnostic methods and in the follow-up, if actually there is already a prostate cancer.
Author: Dr. med. Jörg Zorn