A Prostate-Specific Antigen (PSA) test is a blood test that measures the level of PSA in a sample of your blood. PSA is a protein made by your prostate. The prostate is a gland in the male reproductive system. It lies just below the bladder. It makes the fluid part of semen.

It’s normal to have a low level of PSA in your blood. A high PSA level may be caused by:

• Prostate cancer
• An enlarged prostate (BPH) (benign prostatic hyperplasia)
• Other common prostate problems
• Taking certain medicines

A PSA test can’t show what is causing abnormal PSA levels. So, if your level is high, you may need other tests.