Anything over 600mg/dl is considered dangerously. If it gets over 600mg/dl drink fluids immediately and call your doctor fight away. what is the best blood sugar number? What happens when your blood sugar is too high and what is considered too high What are some symptons of the blood sugar being too high What are good blood sugar levels? I have just been diagnosed with Diabeties 2, and I am wondering what are low level numbers and good numbers, also what is high>? I am asking for two hours after a meal. WHAT IS ACCEPTABLE LEVEL FOR BLOOD SUGAR TEST At what number are blood sugar levels considered an immediate danger? At what number are blood sugar levels considered to low ? sugar level 46