Medical Professional Use Butterfly Needle

A medical professional will use a butterfly needle to draw your blood or to try and access a vein to give intravenous (IV) medications.

Alternatively, they may use an intravenous catheter. It has a retractable needle that’s inside a protective sheath. The needle is inserted into the vein, and then a button is pushed to retract the needle and leave the sheath or catheter.

This is different from a butterfly needle, where the needle gets left in the vein instead of a plastic sheath. However, the butterfly needle is usually smaller in length than an IV catheter.

There are certain cases where one should be chosen over the other. Drawing blood is one of these cases.

A person drawing blood may choose a butterfly needle when drawing blood for the following purposes:

Venipuncture
IV hydration
Medication