The sensation can be surprisingly realistic.
You might suddenly feel as though you are stepping off a ledge, falling down stairs, or slipping from a bed.
Your body then jerks, and you wake up.
Although researchers have proposed several explanations for this phenomenon, the exact mechanism behind the falling sensation is not completely understood.
The important point is that experiencing it occasionally is generally not a sign that something is seriously wrong.
Stress Can Make It Happen More Often
One factor commonly associated with more frequent hypnic jerks is stress.
When you're stressed, your nervous system may remain more alert even when you're trying to sleep.
You may lie in bed feeling physically tired but mentally active.
That heightened arousal can make the transition into sleep less smooth.
As a result, some people notice more frequent twitching during periods of anxiety, emotional stress, or significant life changes.
If you've recently been under pressure and suddenly notice more sleep-start movements, stress may be one contributing factor.
Lack of Sleep May Also Play a Role
Sleep deprivation is another common factor associated with sleep disturbances.
When you're severely tired, your body can move rapidly between different stages of sleep and wakefulness.
If you have been consistently sleeping too little, working long hours, staying up late, or frequently changing your sleep schedule, you may notice more unusual sensations when you finally fall asleep.
Getting sufficient, regular sleep may help reduce these episodes.
Sometimes the simplest explanation is that your body is exhausted.
Caffeine Can Make You More Alert
Caffeine stimulates the central nervous system.