PSA test results: What they mean
What's considered a normal PSA test result varies from man to man. Discuss your results with your doctor to determine how to proceed.By Mayo Clinic Staff
If you've recently had a blood test for prostate-specific antigen (PSA), you may wonder whether your result was normal.
PSA is a protein produced in the prostate, a small gland that sits below a man's bladder. PSA is mostly found in semen, which also is produced in the prostate. Small amounts of PSA ordinarily circulate in the blood.
The PSA test can detect high levels of PSA that may indicate the presence of prostate cancer. However, many other conditions, such as an enlarged or inflamed prostate, can also increase PSA levels.
Results of PSA tests are reported as nanograms of PSA per milliliter of blood (ng/mL). There's no specific cutoff point between a normal and abnormal PSA level. Your doctor might recommend a prostate biopsy based on results of your PSA test and digital rectal exam, along with other factors.
Your doctor may use other ways of interpreting PSA results before making decisions about ordering a biopsy to test for cancerous tissue. These other methods are intended to improve the accuracy of the PSA test as a screening tool.
Variations of the PSA test include:
- PSA velocity. PSA velocity is the change in PSA levels over time. A rapid rise in PSA may indicate the presence of cancer or an aggressive form of cancer.
- Percentage of free PSA. PSA circulates in the blood in two forms — either attached to certain blood proteins or unattached (free). If you have a high PSA level but a low percentage of free PSA, it may be more likely that you have prostate cancer. This test is primarily used for men with a PSA level in the borderline range between 4 and 10 ng/mL. It is especially useful when determining the need for re-biopsy rather than in an initial screening state.
Discuss your PSA test results with your doctor. Together you can decide what your results mean for your health and how you should proceed.
Apr. 28, 2014
See more In-depth
- Prostate cancer. American Cancer Society. http://www.cancer.org/cancer/prostatecancer/detailedguide/index. Accessed March 4, 2013.
- Prostate cancer screening. Centers for Disease Control and Prevention. http://www.cdc.gov/cancer/prostate/basic_info/screening.htm. Accessed March 4, 2013.
- Hoffman RM. Screening for prostate cancer. http://www.uptodate.com/home. Accessed March 4, 2013.
- Castle EP (expert opinion). Mayo Clinic, Phoenix, Ariz. April 17, 2013.