If you can’t press down the insulin when you are injecting, it may be due to subcutaneous hard knots, wrong injection method, clogged needles and so on. 1. Subcutaneous nodules: If you choose the same site for repeated injections for a long time, it will easily lead to the proliferation of subcutaneous fat and the formation of subcutaneous nodules. When there are skin nodules at the injection site, it may lead to the situation of not being able to press down when injecting insulin. 2. Wrong injection method: Due to the improper operation of the patient, the end of the needle is bent and can not communicate with the liquid, which may also lead to the situation of not pressing down when injecting insulin. 3. Needle blockage: some patients use the same needle repeatedly without timely replacement of the needle, insulin residue in the needle resulting in blockage, insulin injection can not be pressed down. It is recommended to consult a medical professional in time when there is an abnormality in insulin injection.