Why You're Struggling to Sleep: Common Causes and What Actually Helps

"I can't sleep" actually describes several distinct patterns — difficulty falling asleep, difficulty staying asleep, waking too early, or sleeping a normal number of hours but waking up feeling unrested — and each pattern tends to point toward a somewhat different underlying cause, which matters considerably for figuring out what will actually help.

Common, Correctable Causes

• Caffeine's long half-life is more relevant than most people assume — caffeine typically takes five to six hours for the body to clear half of it, meaning an afternoon coffee can still be measurably active in the system at bedtime, contributing to lighter or more fragmented sleep even without a noticeable feeling of being "wired."
• Screen exposure before bed delays the body's natural melatonin release through blue light exposure, pushing the onset of sleepiness later than it would otherwise occur.
• An irregular sleep schedule, with wake and bed times shifting significantly day to day, disrupts circadian rhythm consistency in a way that specifically undermines sleep quality over time, even if total sleep duration looks adequate on paper.
• Alcohol before bed, despite its initial sedating effect, actually fragments sleep later in the night — it suppresses REM sleep early on, followed by a rebound effect that causes more awakenings in the second half of the night, which is why alcohol-assisted sleep often feels less restorative than its initial sedating effect would suggest.

When "Insomnia" Is Actually Something Else Entirely

• Sleep apnea causes frequent brief awakenings throughout the night — often too brief to be consciously remembered — that fragment sleep quality without the person necessarily realizing why they wake up feeling unrested despite what seems like a full night's sleep.
• Restless legs syndrome creates an uncomfortable urge to move the legs, particularly at rest, that specifically delays falling asleep.
• Underlying anxiety or depression frequently present with sleep disruption as one of the most prominent symptoms, requiring treatment directed at the underlying condition rather than sleep-focused strategies alone.

Each of these requires a meaningfully different approach than generic sleep hygiene advice, which is part of why persistent sleep difficulty is worth properly evaluating rather than assuming it's simply general "insomnia."

Why Trying Harder to Sleep Can Actually Backfire

A well-documented pattern called the sleep effort paradox describes how the anxiety and frustration of not being able to sleep actually activates the nervous system in a way that makes falling asleep harder still — creating a self-perpetuating cycle where trying harder to sleep becomes part of the problem. A more modern version of this same pattern, sometimes called orthosomnia, involves obsessively checking sleep-tracking data from wearable devices, which can increase anxiety about sleep quality and, ironically, worsen the very sleep difficulty someone is trying to monitor and improve.

CBT-I: The First-Line Treatment Most People Have Never Heard Of