The Cause of Hypnic Jerks While Falling Asleep
Picture this: you are comfortable and safe in your bed, relaxing after a long day and ready for a good night’s sleep. Just as you are drifting off, you are rudely awakened by a fierce jolt to your body. Sound familiar? Scientists estimate that 70% of the population experiences these hypnic jerks at some point in their life.
What is a hypnic jerk?
Between the time you get in bed and when you actually fall asleep, you are in a stage called the “hypnotic stage of consciousness.” The time between when you are awake and asleep is when people are known to have wake induced lucid dreams, but also a time when the brain is susceptible to being jerked back to full consciousness by something small, like muscle jerks.
This is what is happening during a hypnic jerk. The brain is being notified to wake up quickly because something is happening, such as a muscle jerk. The jerks that are experienced during this time can resemble a shock, a flinch, or a quick and intense reaction, depending on the person’s instincts and innate reaction.
It is hard to determine the exact causes and reasons behind hypnagogic jerks. Although none is confirmed, there are several theories as to what causes these sleep disturbances.
There may be medical causes to hypnic jerks such as restless leg syndrome or brain lesions. Because restless legs syndrome is a nervous system disorder, causing an urge to move the legs, this can result in muscle jerks ending in a hypnic jerk. Brain lesions may also cause hypnic jerks, as they alter the activity in the brain and open it up to the possibility of malfunctioning.