During the test
Bilirubin testing is done using a blood sample. Usually, the blood is drawn through a small needle inserted into a vein in the bend of your arm. You'll be asked to roll up your shirt sleeve if you're wearing long sleeves. The person drawing the blood might tie a band around your upper arm and ask you to make a fist. This causes your vein to stand out more, making it easier to insert the needle into the vein. The needle is attached to a small tube, in which your blood is collected. All of this usually takes just a few minutes.
Blood for bilirubin testing in newborns is usually obtained using a sharp lance to break the skin of the heel (heel stick).
You may feel a quick pain as the needle is inserted into your arm and experience some short-term discomfort at the site after the needle is removed.
After the test
Once the needle is removed, a piece of gauze and a bandage or similar material will be placed over the area where the needle was inserted. You'll be asked to gently apply pressure to the area for a minute or so, to help stop any bleeding.
Your blood will be sent to a laboratory for analysis. If the laboratory analysis is done on-site, you could have your test results within hours. If your doctor sends your blood to an off-site laboratory, you may receive the results within several days.