For routine intramuscular injections, the difference in injection sites is the difference between the two. Arm injections are for the deltoid muscle of the upper arm and gluteal injections are for the gluteus maximus muscle.
The muscles in the buttocks are thick and rich in blood vessels. The gluteal injection is usually chosen if the drug dose is larger, more irritating or more painful after the injection. The muscles of the arms are relatively thin. If it is a smaller dose or less irritating medication, an arm shot is appropriate.
The nurse will decide whether to give the arm and or the gluteal injection based on the concentration, dose, and type of medication. Both injections are muscle injections and there is not much difference in the way they are absorbed, so you usually need to choose according to the medication. Patients are advised to actively cooperate with their treatment and follow the advice of their healthcare provider.