Tests for PSA are carried out as a prostate cancer screening test. Typically the range of values are dependent on age and can vary from below 2 to 10.0 ng/mL.

Basis of the PSA test
"Prostate cancer develops from the lining cells of the tiny glands within the prostate whose function is to manufacture PSA. Not surprisingly therefore, prostate cancer cells nearly all continue to secrete PSA. As the cancer grows PSA levels tend to rise."

Increase in accepted PSA cut-off with age
Age	PSA cut-off
40-49 years	2.5 ng/ml
50-59 years	3.5 ng/ml
60-69 years	4.5 ng/ml
Over 70 years	6.5 ng/ml

prostateuk.org

See 'Saw Palmento' as a plant based remedy for enlarging prostate gland