Blood examination of the prostate. Prostate-specific antigen, or PSA, is a protein produced by normal, as well as malignant, cells of the prostate gland.

The PSA test measures the level of PSA in the blood. In addition to prostate cancer, several benign (not cancerous) conditions can cause a person’s PSA level to rise, particularly prostatitis (inflammation of the prostate) and benign prostatic hyperplasia (BPH) (enlargement of the prostate).