When using insulin a low blood glucose reaction also known as hypoglycemia, can occur if you do not eat enough food, skip a meal or exercise more than usual. Signs of hypoglycemia include: confusion, dizziness, feeling shaky, headaches, sudden hunger, sweating and weakness. Hypoglycemia is a serious problem that needs to be treated immediately. If you think you have it eat or drink something sweet like fruit juice or honey IMMEDIATELY.
Attribution: Straight Talk Foundation