The PSA test is a common blood test that helps detect prostate health problems in men, including prostate cancer; this measures the level of prostate-specific antigen, or PSA, in your blood. PSA is a protein produced by the prostate gland. High PSA levels can be a sign of prostate cancer, but they can also indicate other conditions like prostatitis or an enlarged prostate. This test is often recommended for men over 50 and those with a family history of prostate cancer.