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Also known as the “rest and digest” system, our parasympathetic nervous system is vital to health. Learn how things like yawning, taking a coloring book break, and other de-stressors can all lead to better health.
Parasympathetic Nervous System: From Stressed to Rest
The world we live in is far more chaotic and stressful than the one our parents or grandparents existed in. We don’t necessarily have harder things to deal with, but we don’t get a break from the barrage of information.
Life was a different place before the internet, smartphones, and 24/7 news. Our ancestors might have had to deal with famine and saber-tooth tigers, but they at least got a break sometimes. Now our work can follow us everywhere we go. And so can everyone in our social circles via Instagram, Facebook, text messages, and more.
It’s basic human nature to need meaningful amounts of time to decompress. When that doesn’t happen enough, our nervous system can become overloaded. This stress can then lead to a lot of other health problems.
Learn how to support your nervous system with some basic, everyday things you can do at home. Even if you’re really busy (and these days who isn’t??) some of these hacks take literally minutes.
Nervous System Basics
Most people think of the brain when they think of the nervous system. The truth is our entire nervous system is spread all over the body. The whole system’s goal is to send and receive signals.
Afferent nerve fibers (aka axons) send signals from the body to the brain. These signals allow us to rapidly process information. Efferent nerve-fibers have the opposite effect. These fibers carry messages from the nervous system to act on muscles and glands in response to certain stimuli.
The nervous system has several branches with two main control boards:
- The central nervous system (CNS), which is the brain, brainstem, and spinal cord
- The peripheral nervous system (PNS), which is everything else throughout the body
We can break the peripheral nervous system down into two main divisions:
- The somatic nervous system, also called the voluntary nervous system. This includes the sensations and nerve signaling from voluntary movements. Walking, hugging, and moving on our own are all examples of voluntary movements.
- The autonomic nervous system aka the involuntary nervous system. This includes all the nerve-related activity we can’t control and aren’t necessarily aware of. Examples include breathing, heart rate, respiratory rate, digestion, urination, and more.
Parts of Our Autonomic Nervous System
Within the autonomic nervous system, we get even more specific separation.
Sympathetic Nervous System
The sympathetic nervous system (SNS) equips the body to handle a “fight-or-flight response.” This happens via an increase in norepinephrine, epinephrine, and other neurotransmitters.
Cortisol, our adrenal hormone, is also important for SNS activation. This impacts things like the constriction of blood vessels. It also regulates immunity and plays a major role in the inflammation process. Cortisol can increase or decrease inflammation based on the type of pathogens, stressors, or other factors.
While it has its place, we don’t want to always be in a state of high sympathetic system nervous system activity. This causes us to be tense, inflamed, and depleted of what we need to regulate a healthy immune system.
Parasympathetic Nervous System
The parasympathetic nervous system (PSNS) is primarily made up of the vagus nerve. This nerve makes up about 75% of our PSNS. These parasympathetic fibers and nerves connect to nearly every organ in the body.
The vagus nerve and PSNS support the “rest and digest” processes to help rebalance the body. The PSNS helps relax our cardiovascular system, by doing things like dilating blood vessels. This is the total opposite of how the sympathetic nervous system affects blood vessels. The PSNS also influences respiratory health.
Our parasympathetic system is connected to every organ in the body via ganglions and neurons. Because it’s so close to many organs, the PSNS acts as an early warning system for the body. It can detect even slight changes in exposure to pathogens and other inflammatory processes.
Enteric Nervous System
Sometimes called the “gut-brain” the enteric nervous system is the GI tract’s nerve network. It’s made up of nerves that cover the length of the gut. This system runs from the vagus nerve (starting in the brain stem) down to the sacral region of the central nervous system (the lowest part of the spinal cord).
This explains why feeling stressed, anxious, or nervous can cause an almost immediate effect on the smooth muscle of the gut. Sometimes this shows up as nausea, but it can also lead to diarrhea, intestinal pain, or constipation. If you have a nervous gut, it’s not all in your head… but it is heavily influenced by your nervous system.
Whenever there’s dysfunction in our nervous system, the body will always try to restore balance.
Parasympathetic vs. Sympathetic Nervous System
We need a fully operational nervous system, including sympathetic and parasympathetic. They’re both equally essential when it comes to keeping us alive and healthy.
What Does the Parasympathetic Nervous System Do?
The modern, stressful world stimulates our bodies on a sympathetic level. On the flip side, the parasympathetic nervous system lets our body rest, relax, and restore. While it’s often called the “rest and digest” system, it’s also known as the “feed and breed” response.
When we’re always in a “fight or flight” response and in survival mode, our body isn’t working its best.
This is where the idea comes in that stress can cause problems getting pregnant. While it hasn’t been proven that stress alone can cause infertility, there are many links between stress and taking longer to get pregnant.
The parasympathetic nervous system is necessary for many responses in the body we often take for granted. These processes include:
- Activation of the salivary glands and salivation. This is the first important step of digestion.
- Tear production to keep the eyes moisturized.
- Peristalsis, or food moving through the digestive system.
- The release of bile from the gallbladder and pancreas to help digest food.
- Helping with urination by stimulating the bladder to contract and relax to fully empty the bladder.
- Moving waste through the intestines to promote regular, healthy bowel movements.
When we’re chronically stressed everyday bodily functions can become off-balance.
Causes of Parasympathetic Imbalance
The parasympathetic nervous system constantly interacts with the sympathetic and central nervous systems. The body is always striving for homeostasis or balance. Sometimes parts of the nervous system seem to work against each other. At other times, they’re all working toward the same goal.
When we’re under a lot of stress the PSNS fights to counterbalance the effects of the sympathetic nervous system. An imbalanced PSNS can be thanks to one or more of the following triggers:
- Chronic stress from work, relationships, or other mental health challenges
- Not getting a break from parenting, caregiving, or managing too many things at once
- Chronic disease
- Going through a major medical ordeal
- Losing a loved one
- Going through a major move
- Past or present trauma or abuse
Chronic Stress and Cortisol
The adrenal glands produce cortisol to help the body cope with stress. But we don’t have an endless supply of cortisol, our body has to make it. Any time there’s a lot of stress, we need a period of time to rebuild and rebalance hormone stores. Chronic stress can deplete our cortisol, leading to other chronic stress signs like:
- High blood pressure
- Higher heart rate
- Lower heart rate variability
What’s Heart Rate Variability?
Heart rate variability (HRV) is the variation in time between our heartbeats. A good HRV indicates how well we can adapt to stressors and can clue us into how good our vagal tone is. While we don’t want a higher pulse or blood pressure, we do want a higher HRV. A lower HRV means we’re likely more stressed, and not as able to respond to changing circumstances.
Symptoms of Parasympathetic Imbalance
If your nervous system is not balanced, you might have one or more of the following symptoms:
- Frequent headaches
- Fatigue or not feeling rested after sleep
- Getting sick easily
- Insomnia or waking up a lot at night
- Mood swings
- Food cravings or reliance on caffeine, sugar, or carbs
- Dizziness when standing
- Digestive upset, nausea, or bloating
- Acid reflux
- Constipation or diarrhea
- Anxiety or constantly feeling tense
How to Support the Parasympathetic Nervous System
Even if you deal with a lot of stress, there are many ways to support a balanced nervous system response. This involves finding ways to naturally engage and stimulate the parasympathetic nervous system. No matter how busy life gets, it’s easy and free to do this at home.
One of the most popular ways to calm down the nervous system is with deep breathing. Deep breathing exercises support a healthy vagus nerve. They can also reduce stress when we’re faced with a problem right now (like being stuck in traffic).
There are many ways and methods to approach deep breathing. One simple exercise is to breathe in through your nose for 5-6 seconds and exhale through the mouth for 3-4 seconds. Repeat this for as many minutes as it takes to feel calmer.
You can also use deep breathing as part of a formal exercise program, like yoga.
Alternate Nostril Breathing
Alternate nostril breathing is also known as nadi sodhana. This type of breathing exercise supports stress relief and nervous system balance. It’s sometimes taught as a part of pranayama yoga practice.
Here’s how to practice simple alternate nostril breathing for stress-relief:
- Use the thumb and ring finger of one hand to gently close one nostril. Don’t apply enough pressure on there to feel pain, but enough to feel air intake from only the open nostril.
- While blocking one nostril, breathe deeply in through the nose for 5-6 seconds.
- Slowly exhale through the nose.
- Repeat this process with the other nostril.
- Continue alternating nostrils while deep breathing for a few minutes, as often as needed.
It’s hard to imagine life before smartphones. They help us stay in touch through calls, texts, messages, and social media. Scientists estimate we spend about 5 hours a day on our devices and check them an average of 85 times. That’s per day!
Smartphones are also a constant connection to other more stressful types of contact. Work emails, doctor appointments, and those phone calls you really don’t want to answer. They can serve as a constant reminder of being needed, busy, or overbooked. Smartphone use increases stress by affecting our autonomic nervous system and heart health.
Even if we don’t always feel stressed out by our phones, sometimes taking a break can help support our parasympathetic nervous system. A smartphone detox doesn’t have to be all or nothing, either. Here are some options:
- Turn off all notifications
- Limit the use of certain apps, or delete stressful apps off your phone
- Choose a regular day to not use a smartphone
- Don’t use a smartphone for the first or last hours of the day
- Wear blue blocker glasses when using screens after dark. Most devices now have “nighttime mode” that turns down blue light.
Even if you rely on your smartphone for work, no one should be working around the clock. Set office hours and stick to your boundaries. I use a block schedule to make sure I’m prioritizing what I want to.
For someone dealing with stress or fatigue, it’s kind of ironic that yawning can actually help. When we deeply inhale and exhale to yawn, this supports the vagus nerve and boosts PSNS activity. If you find yourself yawning a lot, you might be tired, or maybe your body is just trying to relieve some stress. So don’t fight the urge to yawn, work with it!
Sometimes even reading about yawning or seeing others yawn can be enough to trigger your own. I’ve yawned a few times just writing this!
Exercise is a two-edged sword when it comes to a healthy parasympathetic nervous system. Exercise supports a healthy PSNS, but over-exercising can stress our bodies out.
Stretching is an easy way to relieve muscle tension and stress. Some good options include yoga, pilates, tai chi, or basic stretching. These exercises help us slow down and concentrate on our movements and breathing.
There are formal stretching programs or you can just spend some time focusing on stretches that make you feel better. Raise your arms, touch your toes, whatever works. I like to take stretching breaks throughout the day, especially when I’m working on the computer.
Is there something that brings you joy? It could help stimulate your PSNS! Even if you’re busy and don’t have hours to spend on a hobby, a few minutes here and there on something you love can support the vagus nerve. This could mean:
- Listening to a favorite song
- Reading a book
- Crafting and doing art
- Taking photographs
- Handicrafts like crochet, knitting, or painting
Anything that you love and do for joy can support a healthy “rest and digest” type of response in your body.
Our modern world isn’t built for relaxation. We’re often more tense, overworked, and overwhelmed than our ancestors. The good news is we don’t have to get rid of every aspect of modern life to support a healthy nervous system response. We just have to know how to tap into the parasympathetic nervous system to bring some much-needed balance.
This article was medically reviewed by Dr. Michelle Sands, ND. She is double board certified in Integrative Medicine and Naturopathic Medicine and is also a Board-Certified Holistic Nutritionist, and competitive endurance athlete. As always, this is not personal medical advice and we recommend that you talk with your doctor.
How do you find stress relief? Share your experiences below!
- Andrews S., et al. (2015). Beyond Self-Report: Tools to Compare Estimated and Real-World Smartphone Use. PLoS ONE 10(10): e0139004.
- Askenasy, J. J., & Askenasy, N. (1996). Inhibition of muscle sympathetic nerve activity during yawning. Clinical autonomic research: official journal of the Clinical Autonomic Research Society, 6(4), 237–239.
- Frøkjaer, J. B., et al. (2016). Modulation of vagal tone enhances gastroduodenal motility and reduces somatic pain sensitivity. Neurogastroenterology and motility: the official journal of the European Gastrointestinal Motility Society, 28(4), 592–598.
- Nose, Y., et al. (2017). Association of evening smartphone use with cardiac autonomic nervous activity after awakening in adolescents living in high school dormitories. Child’s nervous system: ChNS : official journal of the International Society for Pediatric Neurosurgery, 33(4), 653–658.
- Rooney, K. L., & Domar, A. D. (2018). The relationship between stress and infertility. Dialogues in clinical neuroscience, 20(1), 41–47.
- Sasselli, V., Pachnis, V., and Burns, A.J. (2012). The enteric nervous system. Developmental Biology, 366(1), 64-73.
- Tyagi, A., et al. (2016). Heart Rate Variability, Flow, Mood and Mental Stress During Yoga Practices in Yoga Practitioners, Non-yoga Practitioners and People with Metabolic Syndrome. Applied psychophysiology and biofeedback, 41(4), 381–393.
- Waxenbaum, J., et al. (2022, Jan). Anatomy, Autonomic Nervous System. Treasure Island (FL): StatPearls Publishing.