IV catheter sizes

IV catheter sizes are measured by gauge, which indicates the diameter of the tube—larger gauges have a smaller diameter, and smaller gauges have a larger diameter. Common sizes range from 14 gauge (larger, for rapid infusion or trauma) to 24 gauge (smaller, for general infusion or children). The choice depends on the patient's needs, such as the type of fluids or medications, and vein size. Larger gauges allow faster flow but cause more discomfort; smaller gauges are gentler but slower. Healthcare providers select the appropriate size to balance comfort, safety, and speed of infusion.