If your sugar is at 75 or lower, you are technically having a low and should treat it with at least 15 grams of fast acting carbs. (My favorite is Capri Sun-its 17 grams and you can slurp it up really fast). Even at around 100 thats when I have some juice or a snack so it doesn't get lower from there. Keep in mind that when having a low it can take 10-20 minutes after treating for you to feel "normal" again.

Are you Type 1 or 2, and for how long?