There are three common places for intramuscular injections. Here is how to locate them:
1. Upper outer portion of the buttocks. Divide one cheek of the buttocks with two imaginary lines into four sections, or quadrants.
Choose the upper-outer quadrant for the shot, but avoid injecting near the major nerve and artery shown in the diagram.
2. The thigh. Choose a point on the outer surface, midway between the hip and knee. Check the diagram to see where this muscle tissue lies.
3. The upper arm (or Deltoid site). This can be found on the upper third of the arm, below the shoulder bone. it is approximately one-third of the way down from your shoulder to your elbow. Looking at the diagram you can see that injecting too low on the arm would bring you close to the major nerves and arteries which you want to avoid.
Intramuscular injections are given with a special needle, inserted deeply and straight into the muscle tissue.
There are many possible places where a subcutaneous shot can be given. Your nurse or physician will probably recommend several which you can alternate using. One site often chosen is the fleshy part of the upper arm, on the outer surface between the shoulder and elbow. In order to reach only the subcutaneous (under the skin) tissues, the correct needle must be used, and inserted at a 45° angle to the skin. See the illustration below, which shows the correct position of the syringe. Remember, only non-irritating medications should be given this way.
Your doctor or nurse will help you select the best size needle for your particular body build and type of injection.
Read The Steps to Giving an Injection
Editor's Note: Adapted from A Comprehensive Guide for Cancer Patients and Their Families. Bull Publishing Company: Palo Alto, CA, 1980. Selection authored by Lizabeth Light, BSN.