- Transient insomnia lasts from days to weeks. It can be
caused by another disorder, by changes in the sleep environment, by the
timing of sleep, or by stress. Its consequences - sleepiness and
impaired psychomotor performance - are similar to those of sleep deprivation. If this form of insomnia continues to occur from time to time, the insomnia is classified as intermittent.
- Acute insomnia is the inability to consistently sleep well for a period of between three weeks to six months.
- Chronic insomnia
lasts from months to years. It can be caused by another disorder, or it
can be a primary disorder. Its effects can vary according to its
causes. They might include sleepiness, muscular fatigue, and/or mental
fatigue; but people with chronic insomnia often show increased
Insomnia is a sleeping disorder characterized by the inability to fall asleep
and/or the inability to remain asleep for a reasonable amount of time.
Insomniacs have been known to complain about being unable to close
their eyes or "rest their mind" for more than a few minutes at a time.
Both organic and non-organic insomnia constitute a sleep disorder.