Insomnia is defined as a difficulty falling or staying asleep or sleep that is simply not refreshing. It can occur for many reasons. It may be related to poor sleep habits or other medical conditions, including psychiatric problems and drug use. It may occur in children. There may not be a clearly identified cause. Insomnia is broken up into the following conditions:
- Adjustment sleep disorder (acute insomnia)
- Psychophysiologic insomnia
- Paradoxical insomnia (formerly sleep state misperception)
- Idiopathic insomnia
- Insomnia due to mental disorder
- Inadequate sleep hygiene
- Behavioral insomnia of childhood
- Sleep-onset association type
- Limit-setting sleep type
- Combined type
- Insomnia due to drug or substance
- Insomnia due to medical condition
- Insomnia not due to a substance or known physiologic condition, unspecified
- Physiologic (organic) insomnia, unspecified; (organic insomnia, NOS)