Why do i jerk awake right before i fall asleep?

Jerk waking, often referred to as a hypnic jerk, is a common phenomenon that occurs as you transition from wakefulness to sleep. It can happen due to the relaxation of muscles and the brain's misinterpretation of this relaxation as a falling sensation. Stress, anxiety, and fatigue can also increase the frequency of these jerks. Generally, they are harmless, though they can be surprising or disruptive to your sleep.