Arterial blood gas

An arterial blood gas (ABG) is a test that measures the levels of certain gases in a sample of your blood. It is usually taken from an artery, a kind of blood vessel that carries oxygen-rich blood away from your heart to the rest of your body. This test can help doctors understand how well your lungs are working and how healthy your blood is. The results can show if you have too much or too little oxygen in your blood, or if there is something wrong with the level of acid in your blood.