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Everything You Need to Know About Activating the Parasympathetic Nervous System

Updated on December 27, 2021
Parasympathetic Nervous System

Sometimes the cause of stress is psychological, such as persistent fear of a family issue, financial problems, meeting deadlines, fear of losing your job, etc. Anxiety can also be triggered by your surroundings, such as trying to be efficient and get your work done fast during a busy workday.

High levels of anxiety, regardless of the cause of the stress, make the human body release stress hormones, inducing physiological changes such as quickened breathing, a racing heart, tense muscles, and increased perspiration. All of these reactions to stress are collectively referred to as the fight or flight response.

Knowing how to manage stress and anxiety by stimulating the parasympathetic nervous system can help you stay calm. It also helps you stay sober for a longer period by lessening the urge to use addictive substances. This article will discuss the benefits of parasympathetic nervous system activation.

An Overview of the Parasympathetic Nervous System

The autonomic nervous system (ANS) regulates the body functions that are outside of voluntary control, meaning it controls all the involuntary or automatic bodily functions. One of its subdivisions is the parasympathetic nervous system.  

This nervous system is also known as the “rest and digest” system. It relaxes a person’s vitals once an emergency or a stressful situation has passed. It also functions to keep the natural activity of the body under control. The activation of this nervous system causes a decrease in arousal.

The decrease in arousal occurs in areas like the glands that secrete saliva, eyes, blood vessels, nerves in the stomach, and nerves present in the bladder. The parasympathetic nervous system (PSNS) starts from the brain and branches out in long fibers. These fibers lead to connecting neurons that are present in the organs they are supposed to act on, allowing fast responses.

The sympathetic nervous system (SNS) is another branch of the PSNS. While the SNS is engaged in activating parts of the body when confronted with stressful conditions, particularly during the fight-or-flight response, the PSNS is frequently stimulated when we are calm or in more ordinary settings.

Functions of the Parasympathetic Nervous System

The parasympathetic nervous system (PSNS) and the organs it influences are associated with a variety of responses. The PSNS can lower the heart rate, especially while at rest after stressful events or after physical activity in which the heart rate has been escalated.

The reaction also constricts the bronchi, causing breathing to slow down and rest. The PSNS causes the pupils to constrict within the eyes. Under stressful conditions, the pupils widen to let more light enter, but this reaction is not necessary for calm situations. The PSNS also causes lacrimation in the eyes or the production of tears. This is to keep the eyes lubricated and protect their sensitive tissues. The PSNS also triggers increased saliva production in the mouth. The salivary enzymes present in the saliva break down the food faster. Hence, the increased saliva secretion enables easier and faster digestion.

Digestion is further promoted by the movement of the stomach and intestines, as well as the release of bile to help the body break down lipids. This movement is known as peristalsis, and the PSNS promotes this motion for elevated digestion. The PSNS also contracts the bladder, causing urination as well as moving food through the intestines and down the digestive system, allowing smooth bowel movements and easier defecation.

The Fight or Flight Response and Parasympathetic Nervous System

As stated earlier, the activation of the sympathetic nervous system prepares our body for the flight or fight response, whereas parasympathetic activation is linked with the body’s normal functioning under relaxed settings.

When the stressor diminishes, the parasympathetic branch of the nervous system gets stimulated. This causes the heart and respiration rates to slow, digestion to resume, and all other processes to return to normal.

After a stressful scenario has passed, the PSNS gets activated, effectively negating all of the work that the SNS has done to excite the body. When the body undergoes stress, the PSNS stimulates the required responses to restore homeostasis. Homeostasis refers to the maintenance of balancing internal physiology.

If we do not have the PSNS, we may either be in a continual state of increased stressed conditions or malfunctioning regulation of our everyday biological functions, such as being unable to regulate our bladder or unable to digest food. Hence, the PSNS plays an important role in both mental and physical health by assisting the body in calming down from the stress reactions that can lead to unfavorable impacts such as high blood pressure.

How Does the Parasympathetic Nervous System Reduce Anxiety?

When the sympathetic nervous system is triggered, the changes in the body occur very swiftly. The brain continues to release corticotropin and adrenocorticotropic hormones until it perceives that the danger has subsided, keeping the body on high alert and prepared for vigorous physical activity.

When the threat is no longer there, cortisol levels drop, and the parasympathetic nervous system lowers the stress response by releasing chemicals that relax the mind and body while blocking or decreasing many of the body's high-energy processes.

Significance of a Balanced Nervous System

Constantly being in a condition of fight or flight is certainly not beneficial for the brain or body. On one hand, you might be suffering from chronic stress, which has many negative implications. Chronic stress has been associated with many diseases. This is primarily due to the link between the immune system and persistent stress.

According to a published study (1), during chronic stress, the neuroimmune axis can get overstimulated and break down, resulting in neuroendocrine/immune imbalances that lead to chronic low-grade inflammation, which can be a precursor to a variety of disorders. Cardiovascular dysfunctions, diabetes, cancer, autoimmune diseases, and mental illnesses such as anxiety disorders and depression have all been linked to both inflammation and stress.

The direct association between chronic stress and the harmful effects it might have on the brain structure cannot be overlooked. These structural alterations can contribute to the emotional, behavioral, and cognitive dysfunctions that are often linked with chronic stress, as well as increased susceptibility to mental disorders.

On the other hand, if our sympathetic nervous system is never activated, we may not be able to deal with dangers effectively. However, for many of us, our sympathetic nervous system and stress response are activated for far longer or more frequently than necessary. This can lead to the aforementioned unfavorable issues, as well as a detrimental impact on your general health.

Nerves of the Parasympathetic Nervous System

PSNS nerve fibers originate in the central nervous system. The cranial nerves are the principal nerves involved. The following are some of the main cranial nerves in the parasympathetic nervous system:

Vagus Nerve: Vagus nerves account for around 75 percent of all parasympathetic nerves. Many important organs, including the kidneys, bladder, stomach, and reproductive organs, contain branches of these nerves.

Oculomotor nerve: The oculomotor nerves are responsible for constricting the pupils.

Glossopharyngeal nerves: These nerves branch out to the salivary glands, supplying the tongue with more saliva. Three of the cranial nerves are also glossopharyngeal nerves.

The PNS is made up of many types of spinal nerves that emerge from the sacral area of the spinal cord (known as S2, S3, and S4). The sacral nerves carry impulses to the reproductive organs, the bladder, and the colon. The axons of these nerves are often fairly long and expand into the ganglia (a collection of neuron cell bodies) throughout the body. Since the ganglia are typically located near the target organs, the PSNS can swiftly send and receive signals throughout the body.

The PSNS is made up of preganglionic and postganglionic neurons, just as the sympathetic branch. Preganglionic nerves originate in the brain stem or the sacral levels of the spinal cord and then branch out to parasympathetic ganglia, which are generally placed near the organs.

After then, the postganglionic neurons will continue their journey to the specific organs and activate them.

Vagus Nerve and the Nervous System

The vagus nerve is the longest and most complex nerve among the brain's 12 pairs of cranial nerves. It sends and receives information from the brain's surface to the tissues and organs throughout the body. The vagus nerve links the brainstem to the body and has two clusters of sensory nerve cell bodies. It enables the brain to keep track of and receive data on a variety of body functions.

The vagus nerve and its associated sections perform a variety of nervous system functions. The autonomic nervous system, which includes the parasympathetic and sympathetic portions, is aided by the vagus nerve. Certain sensory processes and motor information for movement inside the body are controlled by this nerve. It is a portion of a circuit that connects the brain to the neck, heart, lungs, and stomach.

Different Functions of Vagus Nerve

The vagus nerve has four primary functions:

  1. Sensory: The throat, heart, lungs, and belly are all sensory organs.
  2. Special Sensory: The taste sensation is provided behind the tongue.
  3. Motor: It controls the movement of the muscles in the neck that control swallowing and speaking.
  4. Parasympathetic: The digestive tract, breathing, and heart rate are all controlled by the vagus nerve in the parasympathetic nervous system.


Its functions may be divided into seven different groups. One of these is nervous system balance. As mentioned earlier, there are two types of nervous systems: sympathetic and parasympathetic. The sympathetic nervous system elevates energy, alertness, heart rate, blood pressure, and respiratory rate.

The parasympathetic side is highly influenced by the vagus nerve. This system helps with relaxation, calming down, and digestion while lowering blood pressure, alertness, and heart rate. As a result, excretion, urination, and sexual arousal are all supported by the vagus nerve.

Other functions of the vagus nerve include:

  1. Brain and gut communication: The vagus nerve connects the brain and the gut, carrying signals from the gut to the brain.
  2. Calming with deep breathing: The vagus nerve connects with the diaphragm during relaxation and deep breathing. A person feels more comfortable and relaxed when they take deep breaths.
  3. Reduces inflammation: The vagus nerve transmits an anti-inflammatory signal to other regions of the body, which helps to reduce inflammation.
  4. Management of fear: The vagus nerve transmits signals from the stomach to the brain and is associated with anxiety, stress, and fearthus the expression "gut feeling." These signals aid in the recovery of a person from stressful and frightening experiences.

Vagus Nerve Stimulation (VNS)

The stimulation of the vagus nerve is a medical procedure used to treat a range of disorders. It can be carried out manually or with the employment of electrical pulses. Clinical trials have been conducted to determine the efficacy of vagus nerve stimulation. As a result, the Food and Drug Administration (FDA) in the United States has approved its usage to treat two separate disorders: epilepsy and mental illnesses.

Treating Epilepsy With VNS

The FDA approved vagus nerve stimulation (2) for refractory epilepsy in 1997. The procedure involves implanting a tiny electrical device, similar to a pacemaker, in the chest of the patient. The device is connected to the vagus nerve by a small cable called a lead.

Under general anesthesia, the apparatus is surgically implanted in the body. It then transmits electrical impulses to the brain via the vagus nerve at regular intervals throughout the day to lower the severity, or even stop the seizures.

Treating Mental Disorders With VNS

The FDA approved the implementation of vagus nerve stimulation (VNS) as a treatment for depression. It has also been found to aid in the treatment of the following conditions:

  • Alzheimer’s disease
  • Anxiety disorder
  • Rapid cycling bipolar disorder

You do not necessarily have to spend a fortune on a surgery. You can get your hands on our vagus nerve stimulation device. It is completely safe to wear and very comfortable. It seamlessly helps you balance your nervous system and also slows down aging. The device is also very easy to use and you can get relief within minutes!

How to Activate the Parasympathetic Nervous System

When the parasympathetic nervous system is stimulated, the mind and body experience a sense of peace and relaxation. People can learn to activate their parasympathetic nervous system to relieve anxiety and stress instantly. This also improves their mood, boosts their immunity, and lowers their blood pressure.

A person can employ a variety of ways to strengthen and stimulate their parasympathetic nervous system, which causes the body to relax. You can try out the following activities to stimulate the PSNS:

  1. Spend time in the great outdoors or nature.
  2. Consider getting a massage.
  3. Meditate regularly.
  4. Deep abdominal breathing from the diaphragm
  5. Concentrate on a soothing word like calm or peace.
  6. Playing or spending quality time with animals or kids
  7. Exercise
  8. Practicing yoga, tai chi, or chi kung
  9. Experiment with progressive relaxation.
  10. Engage in an enjoyable activity, such as a beloved pastime.

Few More Ways to Stimulate Parasympathetic Nervous System

Touch Your Lips Gently

Were you aware that parasympathetic fibers flow through your lips as well? The parasympathetic nervous system can be stimulated by doing something as easy as passing your finger over your lips. Take one or two fingers and softly move them back and forth on your lips the next time you are feeling anxious or stressed. Yes, even if you are wearing a mask, it works! Concentrate on the sensations this produces and pay attention to how your mind and body start to relax.

Use Imagery

When you need to center yourself and relax, using soothing images to boost the parasympathetic nervous system is a great way to do so. Try imagining yourself in a serene location that you love for a moment. Paint a mental picture vividly of what it looks like. It can be a luscious forest, sunset on the ocean, a private beach, a field of wildflowers, a mountain stream, or wherever else you appreciate and feel at ease.

Envision how at ease you appear while you are there. As you picture the location in these images, use all of your senses. Feel the gentle breeze on your face, hear the waves crashing, and inhale the refreshing scent of the flowers. Take note of every feature, shape, and color in this place. You will discover that you begin to settle down naturally as your mind concentrates on these things rather than the current tension or stressful situation you are experiencing.

Take Deep, Slow Breaths

The parasympathetic nervous system plays a key role in slowing down breathing, as previously mentioned. However, slowing your breathing intentionally, especially during stressful or "fight or flight" situations, can activate the parasympathetic nervous system. You can regularly practice slow and deep breaths from the diaphragm. If you put your palm on your stomach and observe that it rises and falls when you breathe, it indicates that you are breathing from the diaphragm. Diaphragmatic breaths are more soothing and effective than shallow and short breaths linked with the stress response.

Listen to Your Favorite Music When Doing Physical Activity

There is a research study (3) that shows evidence that listening to your favorite music while exercising or doing a physical activity like cycling stimulates the PSNS. You will feel better and calmer. This also helps in reducing the risks of cardiac arrest after a strenuous exercise and induces fast recovery. 

An Overview

The nervous system is quite intricate and complex. The sympathetic nervous system (SNS) and the parasympathetic nervous system (PSNS) are two divisions of the autonomic nervous system. SNS triggers the flight and fight response when stressed or encountering a threat. PSNS triggers the relaxation and calming of the body after the threat subsides. 

Stimulating the PSNS has been discovered to have numerous benefits which mainly involve the control of mental disorders like severe anxiety. It also helps in reducing chronic stress and its associated disorders like cardiovascular disease (4). You can stimulate your PSNS by simply meditating or exercising. Alternatively, you can get a vagus nerve stimulation (VNS) to manage your stress levels and mental issues like depression.

To get the most out of vagus nerve stimulation, try using our tVNS Stimulator. This device is developed with the utmost care by experts to ensure you have the best experience. Take control of your life and enjoy the multiple health benefits of VNS such as improved resilience, better mental health and so much more! To know more about this amazing tVNS Simulator, click here.



  1. Mariotti A. The effects of chronic stress on health: new insights into the molecular mechanisms of brain-body communication. Future Sci OA. 2015;1(3):FSO23. Published 2015 Nov 1. doi:10.4155/fso.15.21
  2. Howland, Robert H. “Vagus Nerve Stimulation.” Current behavioral neuroscience reports vol. 1,2 (2014): 64-73. doi:10.1007/s40473-014-0010-5
  3. Jia, Tiantian et al. “Music Attenuated a Decrease in Parasympathetic Nervous System Activity after Exercise.” PloS one vol. 11,2 e0148648. 3 Feb. 2016, doi:10.1371/journal.pone.0148648
  4. Freeling, Jessica L, and Yifan Li. “Age-related attenuation of parasympathetic control of the heart in mice.” International journal of physiology, pathophysiology and pharmacology vol. 7,3 126-35. 13 Dec. 2015
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