When no cause for the sleepiness can be found, it is called idiopathic hypersomnia.
PROBLEMS STICKING TO A REGULAR SLEEP SCHEDULE
Problems may also occur when you do not stick to a regular sleep and wake schedule. This occurs when people travel between time zones and with shift workers who are on changing schedules, especially nighttime workers.
Disorders that involve a disrupted sleep schedule include:
Irregular sleep-wake syndrome
Jet lag syndrome
Paradoxical insomnia (the person sleeps a different amount than they think they do)
Shift work sleep disorder
Abnormal behaviors during sleep are called parasomnias. They are fairly common in children and include:
REM sleep-behavior disorder (a person moves during REM sleep and may act out dreams)
David B. Merrill, MD, Assistant Clinical Professor of Psychiatry, Department of Psychiatry, Columbia University Medical Center, New York, NY. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.