The prostate specific antigen (PSA) test is used to indicate possible prostate diseases, such as enlarged prostate or cancer, before any symptoms appear, and generally the test range is from about 2.5 nanograms per milliliter or lower below age 50, up to 8 ng/mL at age 80 and well above that if there is cancer or another disease present. Keep in mind that PSA levels can often be a false positive and will also increase with age, and thus can only act as a hint that something MIGHT be going on in the prostate; more testing is needed to see if there actually is.

Normal levels below age 50 are around 2.5 ng/mL. Anything above this level before this age might be cause for concern, which is why it is recommended that most men begin getting regularly tested around age 50 and possibly even as early as 40. After age 50, PSA levels will usually naturally climb, towards about 4 ng/mL by age 60, 7 by age 70, and above by age 80.

The PSA levels increase at least partially because most men will begin having prostate health problems as they age. Either with enlarged prostate, or with prostate cancer, which 80% of men will have by age 80. Since PSA increases with age, then, one of the indicators of a possible problem is a sharp and sudden rise in PSA, outside normal levels, within just a few years.