<unk>  is a circadian rhythm sleep<unk>  which affects people who change their<unk>  or sleep schedules frequently or<unk>  longterm on other than the day<unk> .
Such recurrent interruption of sleep patterns may result in insomnia and/or excessive sleepiness.
A recent study lead in 2007 by the IARC (International Agency for Research on Cancer) has shown that<unk><unk>  could induce cancer .
.
Shift work sleep disorder
Circadian rhythm sleep disorder
Sleep Apnea
Central sleep apnea
Sleep apnea
Nocturnal asthma
Sleep disorder
Delayed sleep phase syndrome