When insulin is injected, there will be overflow residue on the skin surface after the needle is withdrawn, which is a situation often encountered by many glucose patients, especially when using an insulin pen for injection. The overflow when insulin is injected is caused by insufficient injection depth on the one hand, and subcutaneous fibrous tissue growth at the injection site on the other. Fibrous tissue hyperplasia leads to unfavorable absorption of insulin solution, which causes some of the solution to spill out of the skin at the needle hole. In addition, when insulin is injected with insulin pens, due to the small injection pressure, the injection strength is not easy to grasp, and when the injection depth is shallow, there will be drug residue at the needle hole. This not only leads to the waste of insulin, but also the unfavorable absorption will affect the effect of sugar reduction. Suggestion:To avoid overflow of medicine, the depth of insulin injection can be increased appropriately. Generally, it is enough to inject the needle about 3-5 mm and let the needle stay for five seconds after injection before pulling out, which can alleviate the overflow situation to a certain extent. In addition, if the patient’s absorption of the drug is not satisfactory, the injection area can be warmed up with a hot towel after the injection.