What Causes Frequent Urination Along With Excessive Thirst?

I have a 10 year old son, He has been urinating excessively, extremely thirsty, lost 7 pounds in the last month since these symptoms started. I took him to his primary care doc who tested his urine and discovered there was glucose and ketones present. She tested his blood sugar and fasting at this time was 208. She sent us to a childrens hospital to be admitted. When we arrived there my son had not had anything to eat or drink for 20 hours and his blood sugar was 145. They admitted us. They gave him glucola(?) at 27 hours of nothing to eat or drink and no iv and after testing it an hour and 45 min later said blood sugar was 139 and discharged with no explanation except to sy he passed that test. we do have to make a follow up appt with endocrinology for 2 to 4 weeks but my son is a mess. his mouth got so dry yesterday he couldnt even talk and today he has peed 12 times so far. They were not able to have results from an a1c until tomorrow. I am so worried. Is this normal??? Any advice???