i have been feeling very tired just lately so i checked my blood sugar level this morning before i had anything to eat and it was 8.0. i have a book that came with the machine and it says that normal range should be between 3.9 and 5.8 before breakfast for non-diabetics. i checked it again 10 mins ago and its back down to 6.4 which is within normal range. l have also been getting a lot of headaches. i dont want to bother a doctor and take up their time if theres nothing to worry about but i must admit i am confused as to why my blood sugar levels are up and down like a yo-yo. any advice would be greatly appreciated.