Why can't I fall asleep at night?

May 2, 2026 · 8 min read · SleepScience Team

A practical look at why sleep onset gets delayed, including stress, schedule drift, late stimulation, and circadian mismatch.

Trouble falling asleep is often a mismatch between when you want sleep to happen and what your body or mind is still doing.

Why this happens

Stress, late caffeine, erratic sleep timing, bright light exposure, and bedtime rumination can all delay sleep onset.

Falling asleep problems are often about timing and arousal, not simply “not trying hard enough to sleep.”