The PSA test is a blood test used primarily to screen for prostate cancer.

The test measures the amount of prostate-specific antigen (PSA) in your blood. PSA is a protein produced by both cancerous and noncancerous tissue in the prostate, a small gland that sits below the bladder in males.

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, also can increase PSA levels. Therefore, determining what a high PSA score means can be complicated.

There is a lot of conflicting advice about PSA testing. To decide whether to have a PSA test, discuss the issue with your doctor, considering your risk factors and weighing your personal preferences.