Normal blood sugars should range between 70 and 120. I do know that
coma, brain dmg and death can occur when
blood sugars go to
low. That number is different for everyone.
Here are some suggestions, always remember, dont guess, test. Testing is the initial format for your father to know where is at. Second, help your father find a good medical professional to assist with testing, fine tuning insulin intake.
Thanks for the question and I sincerely hope all goes well.