Insomnia is generally classified based on the duration of the problem. Not everyone agrees on one definition, but generally:
- symptoms lasting less than one week are classified as transient insomnia,
- symptoms between one to three weeks are classified as short-term insomnia, and
- those longer than three weeks are classified as chronic insomnia.
Insomnia affects all age groups. Among adults, insomnia affects women more often than men. The incidence tends to increase with age. It is typically more common in people in lower socioeconomic (income) groups, chronic alcoholics, and mental health patients. Stress most commonly triggers short-term or acute insomnia. If you do not address your insomnia, however, it may develop into chronic insomnia.
Many of the causes of transient and short-term insomnia are similar and they include:
- Jet lag
- Changes in shift work
- Excessive or unpleasant noise
- Uncomfortable room temperature (too hot or too cold)
- Stressful situations in life (exam preparation, loss of a loved one, unemployment, divorce, or separation)
- Presence of an acute medical or surgical illness or hospitalization
- Withdrawal from drug, alcohol, sedative, or stimulant medications
- Insomnia related to high altitude (mountains)