The lumps you describe are fat deposits that may occur when insulin is injected into the same general area on a repeated basis.

These lumps can delay the absorption of insulin and cause unwanted glucose fluctuations that trigger low blood sugar, or hypoglycemia.

You should point these areas out to your doctor. In the meantime, you should avoid those areas for injecting to allow time for them to heal.

You should change injection sites to other areas.

Always keep 2 to 5 cm distance between old and new injection site. Something that could be helpful are “injection site templates”.

One easy way to remember to rotate injection sites is to inject on the right side (of the arm, leg, or belly) for any morning and lunch insulin, and on the left side (of the arm, leg, or belly) for the dinner and bedtime insulin.