Hypnic jerks, also known as sleep beginnings, are involuntary muscle contractions that occur as you fall asleep. These jerks usually affect one side of the body and are believed to be caused by a misfire in the brain’s nerve signals during the transition from wakefulness to sleep. Though the exact cause is unclear, hypnic jerks may be linked to factors like excessive caffeine, vigorous exercise close to bedtime, sleep deprivation, and stress. These factors can increase the likelihood of experiencing jerks. While hypnic jerks are generally harmless, they can interfere with sleep quality. To reduce their frequency, try adopting better sleep habits, managing stress, exercising earlier in the day, and minimizing caffeine and nicotine intake. If jerks persist or are accompanied by other unusual movements, consult a doctor