Sleep can be disrupted by insomnia.
Middle-of-the-night insomnia . The disrupted sleep patterns caused by middle-of-the-night insomnia make many sufferers of the condition complain of fatigue the following day . Sleep . Humans may suffer from various sleep disorders , including dyssomnias , such as insomnia , hypersomnia , narcolepsy , and sleep apnea ; parasomnias , such as sleepwalking and REM behavior disorder ; bruxism ; and circadian rhythm sleep disorders .