PSA

Alternative names:

prostate-specific antigen

How the test is performed:

Blood is drawn from a vein (venipuncture), usually from the inside of the elbow or the back of the hand. The puncture site is cleaned with antiseptic, and a tourniquet (elastic band) or blood pressure cuff is placed around the upper arm to apply pressure and restrict blood flow through the vein. This causes veins below the tourniquet to distend (fill with blood). A needle is inserted into the vein, and the blood is collected in air-tight vials or a syringe. During the procedure, the tourniquet 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.

How to prepare for the test:

No special preparation is usually necessary.

How the test will feel:

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.

Why the test is performed:

This test is performed to detect the presence of PSA.

PSA is a glycoprotein in the cytoplasm of prostatic epithelial cells. It can be detected in the blood of all adult men. The PSA level is greatly increased in men with prostatic cancer but can also be increased somewhat in other disorders of the prostate.