My 7 year old son drinks a lot, urinates frequently, is extremely irriatable, complains of headaches and stomachaches, and is always tired even with 10+ hours of sleep. These behaviors come and go with him, but right now they are pretty extreme. At his last year's well child visit, I asked his doctor about the possibility of him being diabetic. They always test his urine for sugar, and told me that he didn't have any sugar in his urine, so he was fine. Is this definitive? His checkup is coming soon and I would like to know if I should ask for a blood test. Thanks!