It is possible to have an insulin reaction during the night. The symptoms might not be the same as a reaction that occurs during the day. Instead, you might have nightmares, sleep poorly, or perspire. In the morning, you may have a dull headache, feel nauseated, feel confused, or complain of being cold during the night. When you test, you might have a 2% or more urine sugar or a high blood sugar reading. This is because the body has "overshot", causing the blood sugar to go very high in response to the low blood sugar you had during the night.

If you suspect this, tell your Doctor. Be sure you are taking your bedtime snack. Do not give yourself more insulin to cover the rise in blood sugar. If you have been taking your snack and following your diet plan, then you must very slowly reduce your insulin dosage according to your Doctor's orders.