Insomnia can be acute (short-term) or chronic (ongoing). Acute insomnia is common and often is brought on by situations such as stress at work, family pressures, or a traumatic event. Acute insomnia lasts for days or weeks.
Chronic insomnia lasts for a month or longer. Most cases of chronic insomnia are secondary, which means they are the symptom or side effect of some other problem. Certain medical conditions, medicines, sleep disorders, and substances can cause secondary insomnia.