Tends to be random, don't get the shakes until 3.0-3.5, get hypo symptoms when my bg rapidly goes down to the 4-5 range from a high bg, if my eyesight go all weird (similar to being drunk) it can be in the 2-3 range. When I feel the shakes under my skin but can't see it, I put it down as a warning sign but always use my libre to verify.