Snapshot A 27-year-old surgery resident works on night float from 8 PM to 8 AM. During the night he notes that he struggles to stay awake and then cannot sleep when he finishes with his shift. He suffers from headaches while he works and feels mildly depressed. At the end of his frist year of residency he has a blood pressure of 130/90 mmHg; while in the past his blood pressure was normally 120/80 mmHg. Introduction Clinical definition incongruence between desired and actual sleep periods differentiate from normal aging (shortening of all phases of sleep with age) subtypes advanced sleep-wake phase disorder early sleep onset and early wake delayed sleep-wake phase disorder late sleep onset and late wake irregular sleep-wake type non-24-hour sleep-wake type Presentation Symptoms tiredness at inappropriate times inability to sleep at appropriate times change in mood Treatment Pharmacologic melatonin effective if taken 5.5 hours before desired sleep Non-pharmacologic full spectrum light therapy best for shift work Other no treatment best for jet lag will resolve spontaneously in < 1 week Sleep hygiene increase exposure to bright/sunlight during the day decrease exposure to blue light at night no consumption of alcohol, nicotine, caffeine or chocolate behavioral modification: only sleep in bed, leave bed if unable to fall asleep in 15 minutes