PSA testing measures the level of prostate-specific antigen (PSA) in the blood, a protein produced by the prostate gland. Elevated PSA levels can indicate potential issues, such as prostate cancer, but can also result from benign conditions like prostatitis or benign prostatic hyperplasia. The test is typically recommended for men over 50 or younger for those with a family history of prostate cancer. While PSA testing can help in early detection, it is not definitive, and further evaluation may be necessary to determine the cause of elevated levels.