What causes insomnia?

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    Last Updated: May 16, 2025

    Insomnia can be caused by several factors, including work stress, relationship issues, traumatic events, medical conditions, medications, and substances like caffeine and alcohol. When it occurs without an identifiable cause, it is referred to as primary insomnia.

    Common causes of insomnia include work stress, relationship issues, or traumatic events. Often times, insomnia occurs in response to certain medical conditions, medicines, and other sleep disorders (e.g., obstructive sleep apnea). Caffeine, tobacco, alcohol, and other substances can also trigger insomnia. However, in some cases, insomnia is considered to be a primary problem because it does not have an identifiable cause, although risk factors include long-lasting emotional upset, stress, travel, and shift work.[1]