What is insomnia?

Insomnia can be short-term, lasting days or weeks, or chronic, occurring at least three nights a week for three months or more. Common causes include stress, anxiety, irregular schedules, caffeine, screens late at night and certain medical conditions. Around one in three adults experiences insomnia symptoms at some point, and roughly 10 percent have chronic insomnia. Poor sleep can affect mood, concentration and long-term health. Cognitive behavioural therapy for insomnia (CBT-I) is recommended as the first-line treatment in many medical guidelines.