There is no cut-off value for PSA above which the test is considered abnormal. There are many factors that influence the interpretation of the results, like your age. Also, a high value on the PSA test does not necessarily mean you have prostate cancer. There are many other causes of an increase in PSA, including other conditions (e.g., infection, benign prostate growth) or recent procedures (e.g., insertion of a catheter or prostate biopsy). A recent DRE or recent ejaculation are also possible causes of elevated PSA in some men. Some medications can also affect the results. Your doctor will need to know what medications you are on to properly interpret the findings of the PSA test.
For PSA testing to work best in detecting prostate cancer, the test needs to be repeated over time (see also the section of this program on the current recommendations for testing). This is important because PSA values may vary from test to test and results may also vary from laboratory to laboratory. Repeated testing provides more certainty that a result is accurate for you.