What are the low and high ranges for blood sugar that are considered the normal average adult values?

Normal Fasting 65-99: For fasting blood sugars, the exact range will vary from lab to lab, but in general 65-99 is considered normal.

Add'l comments: Agree the "normal" range is 60-65 to 99, but want to add it's prob better to think of the development of diabetes as a progression: it's not really that if ur sugar is 99 ur fine & then when it's 100 ur pre-diabetic & at risk. There are several things to look at in determining risk for dm & fasting sugar isn't the best, but if we look at just it, then prob should get ur attention once it's in 90's.

70 to 99: Low range is above 70 whereas your blood sugar should never get over 99 two hours after a meal. If you find numbers after a meal that are in the low 100's you definitely have insulin resistance. Commit to a brink walk for 30 minutes for every high blood sugar and retest after your walk! You can reverse early type two diabetes this way!