Delayed Sleep Phase Disorder (DSPD): A condition where a personâs sleep is delayed by two or more hours beyond the conventional bedtime. Advanced Sleep Phase Disorder (ASPD): A condition where a person goes to sleep earlier and wakes up earlier than most people. Shift Work Sleep Disorder (SWSD): A condition affecting people who work non-traditional hours, such as night shifts or rotating shifts. Non-24-Hour Sleep-Wake Disorder: A condition where a personâs body clock is longer than 24 hours, causing their sleep-wake cycle to drift in and out of sync with the 24-hour day.
