Prostate-Specific Antigen (PSA) Test: What is it?
The prostate-specific antigen (PSA) test measures the level of PSA in a man's blood and is primarily used to screen for prostate cancer. PSA is a protein produced by both normal and cancerous cells in the prostate gland. The test is a straightforward blood test that quantifies the concentration of PSA in the blood, with results reported in nanograms of PSA per milliliter (ng/mL). To perform the PSA test, a healthcare provider will draw blood from a vein, typically in the arm. The sample is then analyzed in a laboratory. The PSA test is conducted when there is a suspicion of issues with the prostate, such as prostate cancer , benign prostatic hyperplasia (BPH), or prostatitis . Traditionally, a PSA level of 4 ng/mL has been considered the threshold between normal and elevated levels. Here is a general guideline: Below 4 ng/mL: PSA levels are usually considered normal. 4 to 10 ng/mL: PSA levels are regarded as slightly elevated. Approximately 25% of men in this range have prostate c...