Common causes of insomnia include stress, an irregular sleep schedule, poor sleeping habits, mental health disorders, physical illnesses and pain, medications, neurological problems, and specific sleep disorders. For many people, a combination of these factors can initiate and exacerbate insomnia.

Not all insomnia is the same. People can experience the condition in distinct ways. How a person is affected by insomnia can vary significantly based on its cause, severity, and how it is influenced by underlying health conditions.