There is no specific normal or abnormal level of PSA in the blood. In the past, PSA levels of 4.0 ng/mL and lower were considered normal. However, some individuals with PSA levels below 4.0 ng/mL have prostate cancer and many with higher PSA levels between 4 and 10 ng/mL do not have prostate cancer (1).
In addition, various factors can cause someone’s PSA level to fluctuate. For example, the PSA level tends to increase with age, prostate gland size, and inflammation or infection. A recent prostate biopsy will also increase the PSA level, as can ejaculation or vigorous exercise (such as cycling) in the 2 days before testing. Conversely, some drugs—including finasteride and dutasteride, which are used to treat BPH—lower the PSA level.
In general, however, the higher a man’s PSA level, the more likely it is that he has prostate cancer.