Long-term insulin injections may cause injection site reactions, hypoglycemia and other adverse reactions. Although long-term insulin injections may have certain adverse reactions, treatment without insulin injections may lead to poor blood glucose control, which will jeopardize the patient’s health even more. It is recommended to follow the doctor’s advice to inject insulin. Insulin is a kind of insulin that can be used to treat type 1 diabetes mellitus, type 2 diabetes mellitus with ineffective dietary control or oral hypoglycemic drugs, diabetic ketoacidosis and other diseases. Insulin treatment is not recommended for people with hypoglycemia and allergies to this medication. Long-term use of insulin therapy may result in injection site reactions, such as subcutaneous fat atrophy and hardening, hypoglycemia, and adverse reactions such as fatty tissue hyperplasia at the injection site. Although long-term use of insulin therapy will have certain adverse reactions, if you choose to stop or reduce treatment without authorization because of the fear of adverse reactions to insulin may lead to poor glycemic control, may induce acute complications such as diabetic ketoacidosis and other acute complications as well as chronic complications such as macrovascular disease, nephropathy, retinopathy, etc., which will jeopardize the patient’s physical health even more. Patients who need to use insulin treatment should standardize the use of medication under the guidance of a doctor, and if there are uncomfortable symptoms after the use of medication, it is recommended to go to the hospital for consultation.