Adverse Effects of Insulin
People taking insulin are susceptible to hypoglycemia when they administer too much insulin, delay or miss a meal, exercise without first eating a snack, or drink alcohol on an empty stomach. That's why insulin treatment requires careful attention to the timing of meals, exercise, and alcohol intake.
If you're taking insulin, you'll also need to test your blood glucose at home, perhaps several times a day. Your doctor will also perform periodic HbA1c tests to check your overall glucose control and to help you find the best doses of insulin that will keep your blood glucose low, but not so low that you have episodes of hypoglycemia.
Other adverse effects of insulin include loss or overgrowth of fat tissue at injection sites, allergic reactions, and insulin resistance. If you inject in the same area over and over again, you may develop fat deposits there, which reduce insulin absorption. This effect is less common with the types of insulin used today, and you can prevent it by rotating injection sites.
Allergic reactions are also less common with the newer insulins. If you suffer reactions, you can be treated with a desensitization procedure that involves starting with injections of small doses of insulin and gradually increasing to higher doses. Insulin resistance, which may be caused by the formation of antibodies against insulin, is usually managed by increasing the insulin dose.