Arterial Blood Gases
How It Feels
Collecting blood from an artery is more
painful than collecting it from a vein because the arteries are deeper and are
protected by nerves.
- Most people feel a brief, sharp pain as the
needle to collect the blood sample enters the artery. If you are given a local
anesthetic, you may feel nothing at all from the needle puncture, or you may
feel a brief sting or pinch as the needle goes through the
- You may feel more pain if the person drawing your blood has a
hard time finding your artery, your artery is narrowed, or if you are very
sensitive to pain.
There is little chance of a problem from having
a blood sample taken from an artery.
- You may get a small bruise at the site. You can
lower the chance of bruising by keeping pressure on the site for at least 10
minutes after the needle is removed (longer if you have bleeding problems or
take blood thinners).
- You may feel lightheaded, faint, dizzy, or
nauseated while the blood is being drawn from your artery.
bleeding can be a problem for people with bleeding disorders. Aspirin, warfarin
(Coumadin), and other blood-thinning medicines can make bleeding more likely.
If you have bleeding or clotting problems, or if you take blood-thinning
medicine, tell your doctor before your blood sample is taken.
rare occasions, the needle may damage a nerve or the artery, causing the artery
to become blocked.
Though problems are rare, be careful with the arm or leg
that had the blood draw. Do not lift or carry objects for about 24 hours after
you have had blood drawn from an artery.
An arterial blood gas (ABG) test measures
the acidity (pH) and levels of oxygen and carbon dioxide in the
The normal values listed here—called a reference range—are just a guide. These ranges vary from lab to lab and depend upon the elevation above sea level. Your lab may have a different range for what's normal. Your lab report should contain the range your lab uses. Also, your doctor will evaluate your results based on your health and other factors. This means that a value that falls outside the normal values listed here may still be normal for you or your lab.