The Parasympathetic Nervous System and Sleep Health
For years, chronic stress and poor coping left my nervous system in overdrive, disrupting my sleep. A wake-up call forced me to explore the autonomic nervous system (ANS) and how shifting from fight-or-flight to rest-and-digest can restore deep sleep. This article explores breathwork, mindfulness, and movement as key tools for nervous system regulation and better rest.
Finding Balance: My Journey with the Nervous System and Sleep
Over the past several years, sleep has been an elusive companion for me. As life’s stresses compounded, I found myself stuck in an endless cycle of exhaustion and unrest. Managing my dad’s revolving health concerns, battling my mental wellness and health struggles, and trying to work through outdated trust wounds while navigating personal relationships—all took a toll on me.
I had long relied on alcohol, wine, and other unhealthy coping mechanisms to suppress my emotions and unwind—unaware of just how deeply I was struggling beneath the surface. As I poured my energy into caring for others (avoiding self-care), my own well-being fell to the wayside. My people-pleasing tendencies kept me pushing forward, even as my body signaled distress.
I dismissed the signs—menopause creeping in, dental work gone wrong disrupting my mouth and gut biome, and underlying health issues like parasite infections and candida overgrowth. To make matters worse, I unknowingly endured over a month of mold exposure last year, further derailing my nervous system health and sleep wellness.
Then came a hard wake-up call.
Two friends, whom I hadn’t spent much time with since our paths had shifted, approached me recently with grievances about my past behaviors—my over-drinking, sharp tongue, and the ways I had projected my pain and struggles onto others. While I had been on my quest for growth and healing, their words reflected a reality I hadn’t fully taken accountability for at the time.
It was painful, a harsh reflection of a time when I didn’t know how to express myself, my struggles, or my mental dysregulation. Drowning in depression and stress, I had never learned how to effectively communicate my feelings or the weight of the toxic emotions I was carrying. While I was grateful that these ladies found the strength to push through my stubbornness and share their concerns, their words felt like a one-sided ambush.
Deep down, I know it came from love. While addressing these behaviors over the past couple of years, I became acutely aware of how much I had been running on an unregulated, overstimulated nervous system. I was incredibly negative, disrupting every part of my life—especially my sleep! And yes… this sleep disruption had been going on for years—far too long. My body had been screaming for my attention, but I still wasn’t fully listening. I was stuck in survival mode.
This wake-up call prompted me to take a deeper look at my sleep patterns and overall health more closely. Let’s explore the autonomic nervous system—how it regulates our stress responses, and most importantly, how we can shift from survival mode into a true state of rest and relaxation.
The Parasympathetic and Sympathetic Nervous Systems in Sleep
Our bodies operate under the guidance of two primary branches of the autonomic nervous system: the sympathetic nervous system (SNS) and the parasympathetic nervous system (PSNS). These two systems work in tandem to regulate stress, relaxation, and overall physiological balance. However, their influence extends far beyond daily activities—they play a critical role in our ability to fall asleep, stay asleep, and wake up feeling refreshed. Understanding how these systems function can help you optimize your sleep and overall well-being.
The Sympathetic Nervous System (SNS): The Fight-or-Flight Response
The SNS is often referred to as the “fight-or-flight” system. When activated, it prepares the body for action by:
- Increasing heart rate and blood pressure
- Releasing stress hormones like cortisol and adrenaline
- Heightening alertness and focus
- Suppressing digestion and relaxation functions
While the SNS is essential for responding to stress and daily challenges, overactivation—especially in the evening—can severely impact sleep. Chronic stress, late-night screen exposure, and stimulants like caffeine can keep the SNS engaged, making it difficult to transition into a restful state. This can lead to symptoms like insomnia, nighttime wakefulness, and restless sleep.
The Parasympathetic Nervous System (PSNS): The Rest-and-Digest Mode
The PSNS is the counterpart to the SNS, promoting relaxation and recovery. It plays a crucial role in sleep by:
- Slowing the heart rate and lowering blood pressure
- Enhancing digestion and nutrient absorption
- Encouraging deep breathing and muscle relaxation
- Reducing stress hormone levels
When the PSNS is dominant, the body naturally transitions into sleep mode, allowing for deeper, more restorative rest. Activities that stimulate the PSNS—such as meditation, deep breathing, and stretching—can help prepare the body for quality sleep.
How an Imbalance Between SNS and PSNS Affects Sleep
If your SNS remains too active at night, you might experience:
- Difficulty falling asleep
- Frequent nighttime awakenings
- Shallow, restless sleep
- Vivid dreams or nightmares due to heightened stress hormone activity
On the other hand, if your PSNS is well-activated before bedtime, you’ll likely experience:
- Faster sleep onset
- Fewer sleep disturbances
- Improved deep sleep and REM cycles
- A more refreshed feeling upon waking
How to Activate the PSNS for Better Sleep
Shifting your nervous system from SNS dominance to PSNS activation is key to a restful night’s sleep. Here are some effective ways to encourage the rest-and-digest mode:
1. Deep Breathing Exercises
Slow, controlled breathing (like box breathing or 4-7-8 breathing) signals the body to relax by engaging the vagus nerve, a crucial component of the PSNS.
2. Reduce Stimulants and Screen Time
Limit nicotine and blue light exposure from screens at least 1-2 hours before bedtime to prevent SNS overactivation.
3. Engage in Gentle Movement
Light stretching, yoga, or a leisurely walk in the evening helps shift the nervous system into relaxation mode.
4. Try Progressive Muscle Relaxation (PMR)
Systematically tensing and relaxing different muscle groups promotes full-body relaxation, easing the transition into sleep. This is something I’ve recently started practicing as a way to reconnect with my body and release stored tension.
5. Create a Wind-Down Routine
Reading, journaling, or listening to calming music can help signal to your body that it’s time to shift gears and prepare for sleep.
6. Use Adaptogenic Herbs or Supplements
Natural options like magnesium, ashwagandha, or L-theanine support PSNS activation and reduce cortisol levels, promoting a smoother sleep cycle.
7. Take a Warm Bath or Shower
A warm bath before bed lowers core body temperature, signaling to your body that it’s time to sleep and encouraging the PSNS response.
Final Thoughts: Rebuilding My Relationship with Sleep
This journey has been about more than just getting better sleep—it’s been about reclaiming my mental health and overall well-being. Losing my mom, navigating difficult relationships, and enduring years of unregulated emotions and stress took a heavy toll on me.
My nervous system had been in a constant state of dysregulation, and in the process, I neglected my own needs. I learned to operate in fight-or-flight mode for so long that true rest and solid sleep seemed impossible. As I began to understand the role of the autonomic nervous system, I realized that healing starts with shifting how I care for myself daily, while retraining and rewiring my thoughts.
Finding balance isn’t about perfection; it’s about self-awareness. Sleep is not just about what happens at night, but how we support our nervous system throughout the day. By making small, intentional changes—whether through breathwork, movement, mindfulness practices, or reducing stress triggers—I am learning to listen to and nurture my body in ways I never prioritized in the past.
