It's possible to have too much insulin and this can cause low blood sugar (hypoglycaemia - sometimes called a 'hypo'). Common symptoms of this are paleness, shaking, hunger and sweating. Your doctor or specialist nurse will explain how to recognize the symptoms of hypoglycaemia and what to do if it happens. E. g, keeping a sugary soft drink handy is a good idea. Occasionally, low blood sugar can cause you to lose consciousness and you will need an injection if this happens. It's a good idea for your family and friends to know what to do if your blood sugar gets very low and you pass out.
Attribution: BUPA