Sleep quality and insomnia in nurses with different circadian chronotypes: morningness and eveningness orientation.

Abstract

Morningness and eveningness preference (chronotype), an endogenous component of the circadian clock could play a key role in a worker's ability for adjusting to shift work. Morning types are those individuals who prefer going to bed and waking up early, whereas Evening types tend to sleep at later hours and find it difficult to get up in the morning.