If the bit is too high (depending on the horse, at three or more wrinkles in the lips), it will irritate the lips, leading to callousing and a loss of sensitivity over time. However, the more immediate consequence is that the horse feels constant bit pressure and cannot get any release, even if the rider loosens the reins. This leads to the horse becoming tense in the jaw and resisting the bit. Most of all, if a too-high bit rubs on the molars, this discomfort will cause the horse to toss its head and otherwise express its displeasure at the situation, leading to a poor performance.