What Is the Vagus Nerve?
What we call the vagus nerve is actually a pair of nerves, one on the right and one on the left side of the body. The human body has 12 cranial nerve pairs, and the vagus nerve is the 10th of these. The cranial nerves emerge directly from the brain or brain stem and relay messages and information between the brain and various parts of the body. (1, 2)
The vagus nerve is the only cranial nerve pair that originates in the cranium, the part of the skull that encloses the brain. Although this versatile nerve has some critical functions in and around the face and throat, it mainly connects the head to other areas of the body. Interestingly enough, it's the only nerve pair to do so. (3)
The word vagus comes from a Latin word meaning “wandering.” This aptly named nerve wanders throughout the body to many vital organs, delivering signals from the brain and relaying messages from the organs back to the brain. These organs include the: (4, 5)
- Digestive tract
- Neck (esophagus, larynx, pharynx)
- Sex organs (females)
The brain has to pass specific pieces of information to all of these organs, and they all — especially the ones in the gut — send information back to the brain. The vagus nerve is essential for this bidirectional communication. (6)
The brain uses the vagus nerve to control the parasympathetic nervous system, which covers the detox, digestion, healing, recovery, and resting aspects of the nervous system. Although the vagus nerve is not the only nerve that controls the body’s ability to decrease stressors, it is by far the most important due to its far-reaching effects. No other nerve has such a widespread impact. (7)
A Deeper Look: The Vagus Nerve, the Mitochondria, and the Cell Danger Response
Well-known for their function as powerhouses of the cells, mitochondria are organelles that produce ATP, the body’s energy currency. But it’s less known that mitochondria also have a substantial role in cellular defense. When under threat, the mitochondria shift from being power plants to defenders. (8, 9)
Mitochondria protect and defend themselves and the body when they face threats from chemicals, heavy metals, infections, physical trauma, psychological trauma, toxins, and other environmental stressors. They do this through a metabolic function known as the cell danger response (CDR) process. Theories around the CDR offer a new outlook for understanding disease. (1, 8, 10, 11)
Metabolic dysfunction causes chronic disease
The CDR is a natural, healthy way for the body to heal itself after threat or injury. As the mitochondria respond to a threat and shift from their normal energy production into the specialized CDR operation, they fight off whatever threatens the body. In short, the CDR protects the cells and the body from harm. (12)
But if the body remains in CDR mode for too long, it can interfere with healing. This is because during CDR, the mitochondria shut down energy production to deal with the threat. In other words, they produce less energy to fuel the body. (8)
If the body doesn’t shift back out of CDR as it should, it remains for too long without proper energy. This can lead to fatigue and illness, and affect the body’s ability to heal itself. With a chronic infection, people typically shift to a prolonged CDR state with low energy production. (13)
This explains why a chronic disease may reappear even after it was believed to have been treated successfully. It’s almost a form of metabolic addiction, where the recovering cell becomes conditioned to remain in an impaired state. (1)
In this situation, it’s important to find what is blocking the body from healing, not what first caused the illness. The bacteria, chemical, toxin, or virus may be long gone, but the CDR process continues, and that’s when an illness becomes chronic. Unblocking the healing process can help fight chronic illness. This is where the vagus nerve comes in. (1)
Stimulating the vagus nerve to switch off the CDR
The ventral branch is linked to the muscles of the face and is tied to our expressions and our desires to be connected to others. When the ventral branch of the vagus nerve is stimulated, we are more social and want to have social interactions. Being social activates our parasympathetic nervous system. (3, 9)
Although our bodies often react to illness, stress, or trauma by entering fight-or-flight mode, this isn’t the only way that they respond. Sometimes, when under threat, our bodies just shut down — they collapse, freeze, or “hibernate” in an attempt to protect us. Think of it as an animal playing dead when it’s in danger. (1)
- Fight-or-flight mode (the sympathetic nervous system response)
- Rest, digest, and heal mode (the parasympathetic response of the ventral vagus nerve)
- Shutdown mode, also known as collapsed, hibernating, or playing-dead mode (the parasympathetic response of the dorsal vagus nerve)
The trick is to get the nervous system to shift to the rest, digest, and heal mode by stimulating the ventral vagus nerve. This will help fight chronic illness, reduce inflammation, and stimulate more healing functions.
When the ventral part of the vagus nerve is in full swing, you feel good. You feel happy and uplifted. You feel socially connected. You are in a state of well-being. And this shows at the cellular level, because the vagus nerve provides communication between the brain and the cells. (1)
The ventral vagus nerve plays a fundamental role in healing, and it’s also the branch of the vagus nerve that gets switched off when the CDR takes over. When the ventral vagus nerve is stimulated, it signals to the body that everything is okay. That way, the body can begin to move away from being stuck in CDR mode and start the healing process. Because everything is connected, what happens at the cellular level also happens at the nervous system level. (15)
The Autonomic Nervous System, HRV, and Vagal Tone
The body’s autonomic nervous system is a part of the peripheral nervous system that controls involuntary processes in the body like blood pressure, digestion, heart rate, and respiration. The autonomic nervous system is subdivided into three components: (14)
- Enteric nervous system (ENS): Controls the movement of the GI tract
- Parasympathetic nervous system (PNS): Relaxation response
- Sympathetic nervous system (SNS): Fight-or-flight response
Among its many other jobs, the vagus nerve controls the parasympathetic branch of your nervous system. That’s the part of your nervous system that stops your body from being overstressed, shuts down the CDR, and keeps you healthy.
So that means that it’s important to keep your vagus nerve in tip-top shape for it to function at its best. When the vagus nerve is working well, so is your body. In other words, when you’re healthy, these things are happening: (10)
- The autonomic nervous system is functioning well.
- The vagal nerve tone is healthy.
- Your sympathetic and parasympathetic nervous systems are in balance.
Your vagus nerve is also in charge of what’s called heart rate variability, or HRV. HRV is a measurement of the variations in time between each beat of your heart. When your body is healthy, it usually has a higher HRV. High HRV is when there is a shorter time between heartbeats. (4, 10)
On the other hand, when your system spends too much time in that unhealthy, stressed-out, fight-or-flight (sympathetic) mode, you’ll have a lower HRV. When your body is in CDR mode, your HRV decreases, as does your vagal tone. (2, 4)
Recent research shows a relationship between low HRV and worsening anxiety or depression. A low HRV is also associated with an increased risk of cardiovascular disease and death (2)
The vagus nerve and HRV are so connected that keeping one in shape usually means that the other will follow. Kind of like a muscle, when your vagus nerve has good tone, that means that it’s strong and healthy. And when your vagus nerve is functioning at its fullest, your HRV will remain higher. All of this leads to your overall wellness.
Bottom line: It’s important to protect your vagus nerve and keep your HRV up so that you can keep yourself healthy.
Support the Mitochondria to Support the Vagus Nerve
Because the vagus nerve and the mitochondria are so interconnected, supporting the mitochondria can support the vagus nerve and vagal tone. Poor vagus nerve function may manifest in many ways, including these symptoms and disorders: (3, 5, 16, 17, 18, 19)
- B12 deficiency
- Chronic fatigue
- Chronic inflammation
- Difficulty swallowing
- Dizziness and fainting
- Gastroparesis (delayed gastric emptying)
- High or low heart rate
- Irritable bowel syndrome
- Weight gain and obesity
Not surprisingly, most of these signs and symptoms of vagus nerve dysfunction are also symptoms of poor mitochondrial function. That means that removing any sources of interference that damage the mitochondria — such as chemical toxins, environmental toxins, EMFs, heavy metals, and forms of infection (bacterial, parasitic, and viral) — may help support the mitochondria and the vagus nerve and help the body heal. (20)
Activating the Vagus Nerve and Reversing the CDR
To combat chronic illness and other issues, the aim is to shut off the fight-or-flight response and exit the dorsal vagus shutdown mode. Then you can reestablish the ventral vagus nerve’s rest, digest, and heal process. Stimulating the vagus nerve helps switch off CDR so that the mitochondria return to energy-producing mode again. (15, 10)
There are many ways to stimulate the vagus nerve every day, simply by incorporating certain activities into your daily routine. You can modify your lifestyle to include some of the following activities and exercises that stimulate the vagus nerve: (21)
Acupuncture may help stimulate the vagus nerve. Research has shown that stimulating the vagus nerve with acupuncture not only helps vagal tone, but it can also help reduce inflammation and produce the feel-good chemical dopamine.
In a study, performing acupuncture on the auricular branch of the vagus nerve (connecting to the ear) caused participants’ heart rates to decrease and their HRVs to increase. For these reasons, using acupuncture to improve HRV can be helpful for many health conditions. Acupuncture is becoming increasingly common and popular for its many health benefits. (22, 23, 24)
Chewing, including both chewing food thoroughly when eating and chewing gum, also activates the vagus nerve. Taking the time to chew food before swallowing it will set the correct digestion sequence in motion and allow the vagus nerve to function as it should. (25)
Enemas trigger the vagus nerve by expanding the bowels. Coffee enemas in particular offer a unique form of cleansing for the liver and bile duct drainage systems. In your body’s detox process, toxins are dumped into the bile, and the toxic bile gets released into the intestines for evacuation.
The body’s entire blood supply normally circulates through the liver every three minutes. Holding a coffee enema for a time will supercharge this cleansing, and the water content of the coffee helps to rinse out the toxic bile. (26)
Cold therapy and cryotherapy have many benefits, including decreasing inflammation, enhancing immune function, and encouraging faster recovery from exercise. Acute cold exposure activates the vagus nerve and the neurons through vagus nerve pathways. That means that cold exposure can also increase parasympathetic activity via the vagus nerve, lowering the fight-or-flight sympathetic response. (27)
Acute cold exposures that can stimulate the vagus nerve include:
- Cold showers
- Cryohelmets or cold vests
- Dipping the face in cold water
- Drinking cold fluids
- Splashing cold water on the face
It’s widely accepted that deep, slow breathing can promote relaxation. Vagal stimulation can lead to relaxation, but the reverse is also true — relaxation can stimulate the vagus nerve. Therefore, inducing a relaxed state through deep breathing can help increase vagal tone. The technique involves breathing slowly as the belly rises and falls to engage the diaphragm muscle. The more the belly expands upon inhale and contracts upon exhale, the deeper the breathing. (6)
Gargling is another way to stimulate the vagus nerve and is an easy exercise to fit into your daily routine. Gargling with a glass of water each morning and night will help to work the muscles in the back of the throat. This activates the vagus nerve and boosts digestive function. If you keep a glass next to the bathroom sink, it can serve as a daily reminder to perform this exercise. Gargling to the point where tears well up in the eyes is even more useful. (28, 29)
Intermittent fasting involves alternating periods of eating with periods of going without food — sometimes for 16 to 24 hours. It can provide many health benefits. Intermittent fasting can boost metabolism, improve mitochondrial and cognitive function, and reduce the risk of diseases. The reason for this may stem from the fact that intermittent fasting can stimulate the vagus nerve and improve vagal tone. It also helps to increase high-frequency HRV. (30)
Laughter is known to provide a range of health benefits. It increases endorphins and blood flow while decreasing pain and stress hormones, which as a result encourages overall well-being. Most importantly, laughter also increases the production of oxytocin, which is thought to help with everything from boosting immunity to fighting depression to lessening schizophrenia-related cognitive problems. (7)
Oxytocin may also improve gut health, which ties in directly with the vagus nerve. When we have healthy microbes in our gut, they send out signals via the vagus nerve that stimulate the production of more oxytocin. (7)
Massage can be beneficial in activating the vagus nerve. Foot reflexology and massages can increase HRV and vagus nerve activity and lower blood pressure and heart rate. (32)
Research also suggests that stimulating the vagus nerve through massage and reflexology can be a successful pain treatment. This effect occurs when the massage and reflexology techniques alter the perception of pain, block pain signals, help regulate emotions, and increase the production of endorphins or neurochemicals. (11)
Massage may also help reduce pain by activating sensory nerves and releasing oxytocin. The primary way that happens is by stimulating the vagus nerve, which affects receptors under the skin and regulates the autonomic nervous system. (11)
Two different types of meditation — loving-kindness meditation and guided mindfulness meditation — have been shown to increase HRV and vagal tone. Chanting alongside meditation stimulates the vagus nerve as well. Regular meditation and positive affirmation can help people achieve better HRV rates. (33, 6)
Along with its other numerous benefits, physical activity seems to help stimulate the vagus nerve. One study found that mild exercise activated the vagal nerve, which then supported the process of emptying the stomach during digestion. Doing some form of exercise can also improve overall digestion. (34, 35, 36)
Singing and vocal exercises
The vagus nerve attaches to the vocal cords, so singing and other vocal exercises can activate it. Energetic singing, hymn-singing, and mantra-chanting all increase HRV in slightly different ways. And loud singing gives the muscles at the back of the throat a workout, activating the vagus nerve. (37, 38)
Being social with friends and family is an excellent way to relax. Positive social interactions also lead to positive emotions, which help improve vagal tone.
Studies have shown a connection between the social engagement system and vagal tone with how people experience social connectedness and positive emotions. In fact, stimulating the ventral vagus nerve through social engagement is a way to get the body to come out of the shutdown or “playing-dead” mode that is associated with the dorsal vagus nerve. (12)
People with higher baseline vagal activity tend to have greater levels of positive emotions, and the opposite effect also occurs: Positive emotions and social engagement influence cardiac vagal tone. Basically, the vagus nerve has a positive effect on social well-being and the ability to cope with social stressors, and vice versa. (12, 39)
Yoga, tai chi, and qigong
Yoga activates the parasympathetic nervous system. It improves blood flow, digestion, lung capacity, and mood and anxiety levels. GABA — a neurotransmitter associated with lifting mood and anxiety — increases in people who perform yoga and other mindful movement exercises. Similarly, studies show that tai chi increases HRV in patients who have coronary artery disease, and qigong can improve HRV in survivors of nasopharyngeal cancer. (40, 41, 42, 6)
- Circadian rhythm management
- Eating healthy foods
- Gratitude journaling
- Improving sleep quality
- Spending time in nature
- Sunlight exposure
- Using essential oils
- Water therapies
Many of these are practical and don’t cost much, yet they really help to reset the nervous system.
The Vagus Nerve Is Your Key to Good Health
The vagus nerve manages key areas of well-being, including digestion, recovery, and rest. You may have cleared different obstacles along your health journey, but if the vagus nerve is stuck in the wrong mode, it can block your progress.
Following some of the above exercises and lifestyle habits may help you feel better, as well as give you a whole new relaxed, calm, and comfortable life experience.
After all, a calm, relaxed emotional state helps encourage recovery. This causes the vagus nerve to signal to the brain and individual cells to initiate healing. This message acknowledges that it’s safe for the body to switch to healing mode.
So remember to take some deep breaths and focus on the inward to encourage your body to stay in the right mode. And if you suspect your vagus nerve isn't working properly, look for ways to stimulate it and increase its activity. A good laugh, massage, or singing session in the shower can do wonders for your health.