What does the gauge of the needle mean?

The gauge of a needle refers to its thickness, with a higher gauge number indicating a thinner needle and a lower gauge number indicating a thicker one. For example, a 21-gauge needle is thicker than a 25-gauge needle. The choice of needle gauge can affect the ease of injection, the type of medication being administered, and the patient's comfort. In general, thinner needles are often used for subcutaneous injections, while thicker needles are used for intramuscular injections.