The following adverse reactions can occur with insulin injections: 1. hypoglycemic reactions: caused by relatively large doses of insulin injections; 2. weight gain: due to the promotion of protein and fat synthesis in the body; 3. refractive error: mostly seen in the early stage of insulin use; 4. edema: due to its mild water and sodium retention effect, usually facial and limb swelling; 5. allergic reactions: can be divided into local and systemic allergic reactions, mainly between patients using insulin of animal origin; 6. It is mainly in patients who use insulin of animal origin; 6. Subcutaneous fat atrophy or abscess: it is mostly seen in patients who use insulin of animal origin and repeatedly inject insulin at the same site; 7. Insulin resistance: it is mostly seen in patients who use insulin of animal origin.