Hypnic Jerks (Sleep Starts): Brief, involuntary muscle twitches that occur when falling asleep. They’re common and usually harmless. Why They Happen: Brain Misinterpretation: Muscle relaxation may be misread as falling, triggering a reflex. Sleep Transition: Different brain parts may fall asleep at different times. Startle Response: Reaction to sudden stimuli or environmental changes. Evolutionary Theory: Possibly a leftover reflex from when primates slept in trees. Common Triggers: Sleep deprivation Stress or anxiety Caffeine/stimulant use Late-night exercise How to Reduce Them: Maintain regular sleep schedule Practice relaxation (e.g., breathing, meditation) Limit caffeine, alcohol, nicotine Create a calm sleep environment Consider magnesium supplements Seek help if symptoms disrupt sleep