Most of your vital bodily systems and their responses are regulated by the autonomic nervous system (ANS) which operates below your conscious awareness. That’s why you don’t have to think about breathing, digestion, or heartbeat. Your brain and body just automatically manage the processes. (Thank goodness!)

The ANS has three branches: the sympathetic nervous system (SNS); the parasympathetic nervous system (PNS); and the enteric nervous system. The PNS, sometimes referred to as the “rest and digest” system, calms your body. The SNS is the “fight or flight” system and is your body’s first responder, getting it ready to run or fight for your life in an emergency. The enteric nervous system regulates your gastrointestinal tract.

The PNS and SNS evolved hand in hand to keep you alive. You need them both. If your SNS were surgically disconnected, you’d live. However, if your PNS were disconnected, you couldn’t survive. The PNS is vital to your mental and physical health and there are many ways you can activate it to benefit you.

Here’s what you need to know.

How Does the Parasympathetic Nervous System Help You?

The PNS puts your body at ease so you can process not only your food but also your emotions. The SNS is your body’s stress response and puts it on alert when it feels your safety and survival are threatened. Just like you can’t drive a car by stomping on the gas and the brake at the same time, it’s best when the SNS, the gas pedal, and the PNS, the brakes, work together in coordination.

Ideally, you want to exist predominantly in a baseline parasympathetic arousal state of calm peacefulness with mild, infrequent SNS activation for enthusiasm, vitality, wholesome passions, and occasional spikes to deal with demanding situations. These days, a lot of us live stress-filled lives where our SNS is activating too frequently or is always “on.” Too much stress and long-term activation of the SNS harms your physical brain and its functioning. Chronic stress makes you forgetful and emotional and increases your susceptibility to anxiety, depression, Alzheimer’s, many mental illnesses, and physical health conditions 

The PNS relaxes and reduces your body’s functions, putting it in a state where it feels calm enough to “rest and digest.” It slows down your heart rate, conserves energy, reduces inflammation, and controls muscle contraction. It also manages many important bodily systems, including digestion, respiration, reproduction, hormone production, cardiovascular regulation, and relaxation. The PNS plays an important role in overall health and well-being because it counterbalances the SNS stress response. Specifically, the PNS controls:


The PNS is closely linked to the respiratory system and helps you regulate the volume and speed of each breath. Breathing is an unusual bodily function in that it’s both involuntary and voluntary. Other vital systems, like digestion or circulation, happen without conscious influence from you. You couldn’t control them if you tried.

Breathing is also managed subconsciously — most of the time. But at any moment, you can take control and change how you breathe which simultaneously alters your emotions and nervous system. Therefore, controlling your breathing is a sure and quick way to consciously choose which nervous system — the PNS or SNS — is activated. Controlled, deep breathing brings more oxygen into your body, slows your heart rate, and engages your PNS instantly.


The PNS also plays a key role in digestion. Stress and anxiety can interrupt the digestive process, making it more difficult to get the full nutrition from your meals. It’s recommended to make sure you are calm before eating. The article, “Relax when you eat – it’s more important than you think,” explains it this way:

“Being in a relaxed state allows the production of adequate digestive enzymes and lets our parasympathetic nervous system — also known as the ‘rest and digest’ system — do its thing. It’s also important to remember that the gut is super connected to emotions, so having feelings of stress and anxiety when we eat is tied to digestive malfunction.”

Heart Rate

The PNS plays a major role in maintaining a healthy heart rate. The primary way it influences heart rate is through the release of acetylcholine, a neurotransmitter that manages some brain and bodily functions, by the vagus nerve. The vagus nerve is the largest cranial nerve in your body, running from your brain stem to your abdomen, with branches extending to internal organs, including the heart. Studies show vagus nerve stimulation lowers blood pressure, decreases heart rate, reduces the body’s response to stress, and improves digestion. By stimulating your vagus nerve, through devices or various DIY methods, you can send the message to your body to relax and reduce stress.


When it comes to managing stress, the PNS can be a valuable tool for anyone. Engaging your PNS can help you manage stress and improve your overall well-being. You can learn to engage your PNS to help you relax, slow your heart rate, and release tension. There are many ways to activate your PNS. These include exercise, meditation, yoga, deep breathing, and even nature walks. When the PNS engages, it initiates the release of relaxing hormones and decreases the production of stress hormones.

Here’s How to Activate Your Parasympathetic Nervous System

Mindfulness Practices

One way to activate your PNS is through mindfulness practices, like yoga, visualization, mindful moments, or meditation. Research is showing that mindfulness practices can have significant positive benefits on mental and physical health. Practicing mindfulness literally changes your brain and body’s default states to be less anxious and more balanced.

Slow Deep Breathing

Taking slow, deep breaths through your nose into your diaphragm with slow exhales engages the PNS instantly and turns down your body’s SNS stress response. It also allows more carbon dioxide to exit your body. Slowing down your breath has many benefits. It’s one of the simplest ways to improve your health, both physically and mentally — and it’s free and not addictive. Relaxed breathing tells your body it’s OK to relax.


Neurofeedback brain training can help turn down your SNS stress response by calming the brain’s fear center, the amygdala. Having a less reactive amygdala takes you out of chronic SNS activation fight-or-flight mode, calms your brain and body, reduces stress hormones, and encourages your brain to operate from a baseline state of PNS activation. In this state, your brain and body will be calmer, healthier, happier, and more relaxed.

A Calmer Brain Means a Calmer You

Our Grey Matters professionals understand your nervous system and know how to guide it to a calmer state. Our brain training experts can literally retrain your brain to perform better — in a way that alleviates problematic mental and physical symptoms for you.

Neurofeedback successfully improves many conditions, including depression, anxiety, autism, ADD and ADHD, brain injuries, OCD, stroke recovery, PTSD, addictions, seizure disorders, migraines, chronic pain, IBS and gut issues, and more. By fine-tuning the brain’s performance, neurofeedback can also improve focus and concentration. For example, neurofeedback brain training could enhance a person’s performance at school, golf or other sports, or work.

At Grey Matters, we are passionate about helping people live their best lives. Give us a call at (317) 215-7208 or send a message today to find out how we can help you.