Gas bubbles in insulin pens may be due to improper operation, too long opening time, improper preservation and other reasons. 1. Improper operation: For any insulin pen, it should be ventilated before injection, the tip of the pen should be erected upward, and 1-2 units should be adjusted to hit until the gas is emptied, so as to avoid the gas bubbles remaining in the insulin; for premixed insulin, it needs to be shaken evenly before use, but the action should be gentle, and too violent shaking will lead to the generation of gas bubbles. 2. Too long opening time and improper preservation: insulin pens should be used up within one month after opening, and should be discarded after more than one month, otherwise the insulin will easily produce bubbles after deterioration; secondly, after opening, insulin pens should be kept in a cool place, avoiding sunlight and overheating, otherwise it is easy to inactivate and deteriorate insulin, and produce bubbles. A small amount of air bubbles during the use of insulin pens is a normal phenomenon, remember to exhaust the air bubbles in the pen before injection, if too many bubbles can not be discharged, it should be replaced in a timely manner, and continue to use the risk of drug failure, air embolism and so on. The use of insulin pens should be reasonably operated and standardized under the guidance of a doctor to avoid adverse consequences.