You rest onto your bed and begin shifting into warm, lulling sleep and suddenly your body jerks.
When someone is beginning to fall asleep, some dream or his imagination causing him to awake suddenly. This is known as Hypnic Jerks. Almost 70% of people experience this while sleeping.
These sleep state occurs during period of being awake and asleep, a.k.a. hypnagogic stage. This is stage where you’re in some sort of dozy and thoughts blend into indefinite dreams. That’s when you yourself does not know whether you’re awake or sleeping.
These starts are due to an involuntary muscle jerk or trigger by some external light or sound.
Hypnic jerks are nothing to worry about, it’s just the brain’s reaction to a condition when muscles begin to relax and loosen up. The brain mistakes it to as a indication of falling and tenses and tries to ready the body to stop the fall.
The most common cause is anxiety which is something we all have nowadays thanks to a paced life. Anxiety disturbs the sleep patterns and medical research reveals that these jerks vary in frequency according to level of stress.
Another reason is sleeping disorders like narcolepsy. So, while booze-up watching TV series at late night is probably not the right idea. This cause changes in neuro-transmission, when the nerves ‘misfire’ in someway and this advances to hypnic jerks.
In some cases, hypnic jerks are the consequences of restless leg syndrome.
Though in many cases, restless leg syndrome is consider to be hereditary, it can also be due to alcohol abuse, sleep deprivation, diabetes and kidney failure.
Another reason might be brain lesions, especially close to the pyramidal tract of brain. It is associated with our body movements. Lesions can cause involuntary movement when the body transitions to sleep.