PSA

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Blood test

The PSA test measures the amount of PSA (prostate-specific antigen) in the blood.

Prostate-specific antigen; Prostate cancer screening test 

Blood is drawn from a vein, usually from the inside of the elbow or the back of the hand. The puncture site is cleaned with antiseptic. An elastic band is placed around the upper arm to apply pressure and cause the vein to swell with blood.

A needle is inserted into the vein, and the blood is collected in an air-tight vial or a syringe. During the procedure, the band is removed to restore circulation. Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.

No special preparation is usually necessary. It is not necessary to fast (refrain from eating) prior to the test. Falsely elevated results can be due to a recent urinary tract infection, enlarged prostate gland, prostatitis, or recent placement of a urinary catheter or surgery on the urinary tract.

Discuss with your doctor or health care provider whether a PSA test is appropriate for you, because it is not appropriate for all men.

When the needle is inserted to draw blood, some people feel moderate pain while others feel only a prick or stinging sensation. Afterward, there may be some throbbing or a bruise.

This test is performed to detect the presence of PSA in the blood. High PSA level has been linked to an increased chance of having, but does not mean that the person definitely has, prostate cancer. Several conditions besides cancer can cause the PSA level to rise. These include urinary tract infection, benign prostatic hypertrophy (BPH -- an enlarged prostate), and prostatitis.

PSA is a glycoprotein (a protein with a sugar attached) found in prostate cells. It can be detected at a low level in the blood of all adult men.

Review Date: 11/23/2005
Reviewed By: David R. Knowles, M.D., Advanced Urologic Surgeons, Mt. Vernon, IL. Review provided by VeriMed Healthcare Network.