Why Do I Feel More Anxious After a Bad Night’s Sleep?
Poor sleep increases anxiety because it disrupts emotional regulation. When you miss deep and REM sleep, the brain becomes more reactive to stress and less able to regulate fear and worry.
REM sleep helps process emotions
REM sleep plays a key role in emotional regulation. During REM, the brain processes emotional memories and dampens the intensity of stress responses.
Sleep deprivation heightens threat perception
After poor sleep, the brain’s threat-detection systems become overactive. This makes everyday situations feel more overwhelming and emotionally charged.
- Increased emotional reactivity
- Lower tolerance for stress
- Reduced ability to self-soothe
The amygdala becomes more reactive
Research shows that sleep loss increases activity in the amygdala — the brain’s fear center — while reducing communication with regulatory regions in the prefrontal cortex.
Why anxiety can feel physical after bad sleep
Poor sleep increases stress hormones and nervous system arousal. This can amplify physical symptoms of anxiety such as tension, restlessness, and a racing heart.
Quick FAQs
Yes. Even a single night of poor sleep can increase emotional reactivity and anxiety the next day.
For many people, improving sleep quality significantly improves emotional regulation and stress resilience.
Often both. Poor sleep increases anxiety, and anxiety further disrupts sleep — creating a reinforcing cycle.
