Hello there I have read through your question and would like to tell you that though we have specific symptoms for hypoglycemia like dizziness, fainting but there are no specific symptoms or fixed level of hyperglycemia. Patient with high blood glucose levels may experience symptoms like burning sensation in feet , frequent urinary tract infection, non healing of wounds etc. But some times patients with blood sugar levels as high as 350 do not experience any symptoms . So the best way to avoid any complications like diabetic ketoacidosis and renal nephropathy it is better to do regular monitoring of blood sugar levels. I hope that answers your question. If you have any further questions please feel free to write. Thank you for choosing healthcare magic.