Insomnia

What Causes Insomnia? 8 Common Triggers Explained

Stress, caffeine, hidden medical issues — here are the most common drivers of chronic insomnia and what to do about each.

January 12, 20267 min readInsomnia

Stress and anxiety

Roughly 60% of acute insomnia cases trace back to a stressful life event. Cortisol spikes at night keep the brain in an alert state and prevent sleep onset.

Irregular sleep schedule

Going to bed at different times every night confuses your circadian rhythm. A consistent wake time is the single most powerful anchor for healthy sleep.

Caffeine and stimulants

Caffeine has a 5–7 hour half-life. An afternoon cup can still measurably reduce deep sleep that night.

Evening screen use

Bright blue light after sunset suppresses melatonin by up to 50%, delaying sleep onset by 30–60 minutes.

Underlying medical conditions

Thyroid disorders, chronic pain, GERD and sleep apnea can all present as insomnia. Persistent insomnia warrants a medical workup.

When to seek help

If trouble sleeping occurs more than three nights per week for over three months, ask your physician about CBT-I — the gold-standard treatment for chronic insomnia.

Editorial standards

Last reviewed January 2026 against current US sleep medicine guidelines by the Sleep Disorder Symptoms editorial team. This article is educational and is not medical advice — see our medical disclaimer and editorial policy.

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