What is a healthy prostate-specific antigen level range?

There is not a normal range for prostate-specific antigen levels in the blood, states the National Cancer Institute. Even so, most doctors believe that a PSA level of 4 nanograms per milliliter of blood and lower is normal.

Since there is not a scientific normal range for prostate-specific antigen levels in the blood, doctors often look for a change in the level to determine if prostate cancer is present, states the National Cancer Institute. If a man has rising levels of his prostate-specific antigens, then further testing may be necessary in order to determine if he has prostate cancer or not.