Many people believe that eight hours of sleep guarantees feeling refreshed the next morning. However, if you often wake up exhausted, restless, sweating, or craving sugar, the cause may go beyond just sleep duration. The underlying issue frequently involves a misalignment between cortisol, the body’s stress hormone, and your circadian rhythm, which regulates sleep-wake cycles. When these systems are disrupted, your nervous system can remain in a heightened state of alert throughout the night. This fight-or-flight activation prevents the body from entering deep, restorative sleep, leaving you tired despite sufficient hours in bed. Addressing cortisol balance and circadian alignment is essential for truly refreshing rest.





How cortisol imbalance disrupts sleep and keeps you wired



Cortisol, known as the stress hormone, naturally fluctuates throughout the day. It helps regulate metabolism, blood sugar, and the body’s stress response. Ideally, cortisol levels peak in the morning to help you wake up and gradually decline at night, allowing your body to relax.



When cortisol remains elevated during sleep, your nervous system stays in a state of sympathetic dominance, also known as fight-or-flight mode. This prevents the parasympathetic system, which controls rest and recovery, from taking over. The result is fragmented sleep, racing thoughts, and the feeling of being tired yet wired in the morning.





Common sleep behaviours that indicate stress





Certain sleep behaviours are key indicators that your nervous system is under stress. This highlights patterns that should not be ignored:

• Waking up sweating

Night sweats can occur when cortisol and adrenaline levels are elevated. The body attempts to cool itself down, but this also indicates a heightened stress response that interrupts restorative sleep.

• Grinding teeth or clenching the jaw

Jaw tension is a common outlet for stress and anxiety. Grinding or clenching teeth during sleep can indicate that the body is releasing stress, often linked to gut issues, anxiety, or poor recovery.

• Frequent nightmares

A brain overstimulated by stress chemicals can disrupt REM sleep, causing frequent or intense nightmares. These interruptions prevent the brain from completing essential cycles of memory consolidation and emotional processing.

• Sleeping with T-Rex arms

Curled arms during sleep are often a sign that the body is still holding on to tension. This posture suggests that the nervous system remains partially activated, limiting deep restorative sleep.

• Talking in your sleep

Sleep talking can occur when the mind is still processing emotions. This reflects incomplete relaxation and indicates that your body has not fully transitioned into deep sleep.

• Sleepwalking

Sleepwalking is another sign of an overactive stress response. The body moves even while the mind should be resting, showing that the sympathetic nervous system remains engaged.

• Waking up multiple times at night

Frequent awakenings can be caused by sudden cortisol spikes or gut imbalances. These disturbances prevent the body from completing full sleep cycles, resulting in daytime fatigue.

• Difficulty falling asleep

Difficulty initiating sleep often reflects a flipped cortisol rhythm, where your stress hormone is elevated at the wrong time. This prevents the body from entering a relaxed state conducive to sleep.







Strategies to regulate your nervous system and improve sleep



Regulating the nervous system is crucial for restorative sleep. Experts suggest several practical methods to activate the parasympathetic system:

• Slow diaphragmatic breathing

Deep, slow breathing stimulates the vagus nerve, encouraging a parasympathetic response and signalling the body to rest. Practising this technique before bed can significantly improve sleep quality .

• Cold exposure

Splashing cold water on the face or taking a cold shower stimulates the vagus nerve, helping reset the nervous system and reduce sympathetic overactivation.

• Grounding techniques

Engaging in sensory-focused activities, such as walking barefoot, handling textured objects, or focusing on bodily sensations, helps reduce arousal in the nervous system and promotes relaxation.

• Vagal nerve stimulation

Humming, singing, or gargling activates the vagus nerve, which supports a calmer state and improved sleep quality.





Maintaining routine sleep and nutrition



Consistent sleep and meal schedules stabilise circadian rhythms and blood sugar levels, supporting nervous system balance. Prioritising seven to nine hours of sleep, regular exercise, and balanced meals enhances recovery and stress resilience.





Lifestyle habits that support deep restorative sleep



In addition to nervous system regulation , lifestyle choices play a crucial role in improving sleep quality. Limiting screen exposure before bed, creating a calming pre-sleep routine, and avoiding stimulants like caffeine in the evening can help. Combining these habits with regular breath work, grounding practices, and proper nutrition ensures the body and brain are prepared for restorative rest.








Disclaimer: This article is based on publicly available information and expert advice. Consult a healthcare professional before making significant changes to your sleep routine or lifestyle.