Insomnia may be temporary (called situational insomnia) or ongoing (chronic insomnia). Situational insomnia occurs
with a stressful event. It is often caused by noise, pain, worry, or family, work, financial, or school problems. It lasts 3
weeks or less. This kind of insomnia generally goes away when the stressful event is over or resolved.
Chronic insomnia can be caused by irregular sleep-wake patterns resulting from shift work, drug dependency
(including long-term use of sleeping pills or alcohol), stress, illness, or mental health problems such as anxiety or
depression. It lasts longer than 3 weeks and requires treatment of the underlying problem.