When my BG drops slowly, my body has time to adjust, and I don't feel the lows until I am below 50. When I drop fast, my body does not have time to adjust, so I feel the low in the 70's, and sometimes in the low 80's. When I treat, I see how many points I need to reach 100. I divide that number by 3 since that is how much my BG will typically rise for each carb I eat. If I have insulin on board from a previous bolus, I take that into account. Then I know how many fast acting carbs I need. I am so used to doing this that I can determine the number of carbs I need very quickly. The result may not work exactly as planned, but it rarely results in a very high BG after treating. This routine is much better for me than "eating the whole contents of the fridge" like some people say they do, lol. Some people say they go to the kitchen during a low, and that will sometimes involve going downstairs. I have even heard people having a low that is so bad that they have to crawl to the kitchen. Why do people do that? Please keep some fast acting carbs with you at all times, especially within easy reach at night. Glucose tabs, jelly beans, etc. I have a zip-lock bag of jelly beans or Skittles in my pants pocket when away from home, and I always have glucose tabs or fast acting candy within reach when at home.
I am using a Dexcom G4 CGM now. I can see oncoming lows, and eat some fast acting carbs before I have a hypo. That is so much better than having a hypo, and treating before my BG goes dangerously low.