Insomnia can be:
* Transient (short term) insomnia lasts from a single night to a few weeks.
* Intermittent (on and off) insomnia is short term, which happens from time to time.
* Chronic (on-going) insomnia occurs at least 3 nights a week over a month or more.
Chronic insomnia is either primary or secondary:
* Primary insomnia is not related to any other health problem.
* Secondary insomnia can be caused by a medical condition (such as cancer, asthma, or arthritis), drugs, stress or a mental health problem (such as depression), or a poor sleep environment (such as too much light or noise, or a bed partner who snores).
Source: U.S. Department of Health and Human Services