My grandson woke up Sunday, vomited and went back to sleep. He repeated this 3-4 times, throwing up and laying back down and falling asleep. This was not normal. Usually, when he gets up he stays up and active. He did not drink as much as normal, and his vomiting produced small amounts stomach fluid. That afternoon, he ate a little bit and perked up and seemed to be fine. On his ride home, he became very lethargic and non-responsive to verbal stimuli while in the car. He was taken to the hospital ER at that point. The ER suggested that he may have ingested something to cause his problems. Could low sugar cause the symptoms above and would it normally be looked for in a 3 year old boy in this situation?