In most cases, an artery on the palm side of the wrist is used to get the blood. Sometimes, an artery in the groin or other area is used to get blood. The skin over the artery is first cleaned. Next, a small needle is inserted through the skin and into the artery. The needle is usually hooked up to a syringe.
Blood flows into the syringe once the needle is put into the artery.
Pressure is applied over the area after the blood is collected to prevent bleeding. The blood is then sent to the lab for analysis. No preparation is generally needed for this test. A healthcare provider will give any instructions if needed. Each of the values has a set range that is considered normal.