1. Health
You can opt-out at any time. Please refer to our privacy policy for contact information.

Discuss in my forum

Definition of Hypnagogic Jerk


Updated February 18, 2014

Definition: A hypnagogic jerk is an involuntary myoclonic twitch, or muscle contraction, that occurs while an individual is beginning to fall asleep. There may be a sensation of falling followed by a physical jerk back into wakefulness. It usually occurs during stage 1 sleep which is the lightest stage of sleep.
Also Known As: Hypnic jerk, Sleep starts
When I fall asleep, I startle myself back awake with a hypnagogic jerk.

©2014 About.com. All rights reserved.

We comply with the HONcode standard
for trustworthy health
information: verify here.