For diabetic patients, keeping blood glucose stable and strengthening blood glucose control is the top priority. Blood glucose value is not only the basis for doctors to use medication, but also diabetic patients need to understand the development of their disease and the effect of treatment through this indicator. Because of its easy, fast and accurate operation, blood glucose meter has gradually become a necessary home testing instrument in life, which is loved and respected by the majority of patients. Some diabetic patients also use insulin intensive therapy to control their blood sugar. Intensive insulin therapy is to flexibly adjust the insulin dose according to the amount of carbohydrates and physical activity of the patient’s meals, and to use subcutaneous insulin injection or insulin pump therapy several times a day, so that the blood sugar of sugar lovers can be ideally controlled. The popularity of blood glucose meters and insulin therapy has benefited countless diabetic patients, but the resulting problems cannot be ignored. The continuous consumption of consumables such as needles has led many patients to share needles with their families or use needles repeatedly as a result of saving financial expenses. Ms. Li (a pseudonym), who lives in Nanjing, is only 39 years old, but has been suffering from diabetes for more than a decade, and her mother is also a type 2 diabetic who has been treated with insulin injections to control her blood sugar. Recently, Ms. Li and her mother’s blood glucose had been poorly controlled, so they came to the endocrinology department of PLA Hospital No. 454 with her mother for inpatient treatment. As Ms. Li’s attending physician, I found out that Ms. Li had been sharing needles with her mother for blood glucose testing and insulin injection in order to save money, and even some relatives at home would occasionally go to their home to use the used needles to test their blood glucose. What was even more unexpected was that during the subsequent physical examinations, Ms. Li was found to be suffering from hepatitis B. This scared her family, and the whole family rushed to the hospital for the examination. Here we emphasize: reuse of insulin syringes and needles is harmful! Diabetic patients must be aware that both special syringes and needles of insulin pens are disposable, which means that the needles should be replaced after one injection. However, the fact is that many diabetic patients are reusing insulin syringes. Diabetic patients should pay attention and standardize insulin injections. So, what harm will repeated use of syringes or needles bring to the body? First, repeated use can cause burrs, bends, and barbs in the needle tip, which can lead to bleeding and bruising at the injection site and can also increase pain. Then, repeated use of deformed needles can cause micro trauma to the subcutaneous tissue, which over time can lead to the development of subcutaneous fatty nodules. The hard knots will lead to a decrease in insulin absorption rate and longer absorption time, and make it more difficult to control blood sugar. Finally, and most importantly, after repeated use, bacteria in the air and on the needle tip can enter the refill through the syringe, contaminating both the medication and increasing the risk of local infection.