Poor sleep and anxiety show up together so often that it's worth asking which one started it — and the honest answer is usually: both, feeding each other.
A loop, not a one-way street
Research suggests the relationship runs in both directions. Anxiety can make it harder to fall or stay asleep, and poor sleep can lower your threshold for stress and worry the next day. Each bad night makes the next day's worry a little easier to trigger.
Anticipatory anxiety about sleep itself
One specific pattern worth naming: worry about whether you'll be able to sleep tonight, often starting well before bedtime. That anticipation is itself a form of physiological arousal, which makes falling asleep harder — the worry about not sleeping becomes part of what prevents sleep.
- General anxiety that shows up throughout the day, not just at bedtime.
- Sleep-specific anxiety — dread of bedtime itself, clock-watching, "what if tonight is bad too."
- Physical arousal — a racing heart or tense body that anxiety and sleeplessness both produce.
CBT-I can reduce sleep-related anxiety specifically, while general anxiety treatment can reduce the racing-thought pattern that interferes with sleep. Many people find they need to address both pieces, not just one.
Which to prioritize first
If worry feels like a bigger theme in your life than sleep specifically, it may be worth looking at anxiety on its own terms, alongside whatever sleep habits you're adjusting. Neither piece has to wait for the other to be perfect before you start.