What does SQ stand for in injection terminology?

• A. Subcutaneous
• B. Subdermal
• C. Superficial
• D. Superior

Answer: (A)

The main idea is that SQ stands for the subcutaneous route, meaning the injection goes into the tissue just beneath the skin. This tissue layer is primarily fat and connective tissue, so injections here are absorbed more slowly than intramuscular injections but faster than dermal or topical applications. Subcutaneous injections are a common route for vaccines and medications where deeper tissue isn’t needed.

Subdermal isn’t the standard term used in injection practice, and while some people might hear it, the accepted and precise term is subcutaneous. Superficial refers to something near the surface and doesn’t specify the tissue plane for injections, and superior is an anatomical directional term meaning “above,” not a depth or tissue layer. So the correct expansion of SQ in injection terminology is subcutaneous.