Recognizing Vagus Nerve Dysfunction

Emotional, Physiologic, Structural Causes, Cranial Nerve Symptoms, Abnormal Muscle Tone, Gastrointestinal, Cardiovascular, Inflammatory & Psychiatric Symptoms, Understanding Vagal Tone

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The vagus is one of my favorite topics to teach about because it connects so many dots between our mind, body, and even spirit. When it’s working well, there are endless benefits; however, when it’s not, we can see a range of seemingly unrelated physical and brain symptoms, including anxiety, depression, panic, and dissociation.

In a recent newsletter, I discussed the vagus nerve's role in our sense of safety and our ability to engage with others. I discussed how social interaction is one way to access the vagus nerve. In this post, I’ll address the causes of vagal nerve dysfunction, including structural issues and signs and symptoms to help you recognize autonomic or vagal nerve dysfunction.

Refresher

The vagus nerve is part of the autonomic nervous system that controls automatic functions in the body beyond the brain’s conscious awareness.

The Autonomic Nervous System includes:

• Sympathetic Nervous System - puts our body into fight or flight by moving blood to the heart and muscles (to help us move fast) and away from the digestive tract.

• Parasympathetic Nervous System- is the BRAKE on the sympathetic nervous system that allows us to rest and digest. The vagus - the main component - helps us mitigate the impact of stress on the body so we can return to a calm state.

  • Dr. Stephen Porges’ Polyvagal Theory emphasizes that 2 separate nerves/branches coming from 2 separate areas of the brain fuse to become the vagus. 

    • Dorsal Vagus -  relates to the shutdown/freeze/immobilization response (a third defense mechanism different from fight or flight).

    • Ventral Vagus - especially important in social communication.

Jobs of the Vagus

• Release the neurotransmitter acetylcholine to counteract the effects of adrenaline and tell our body to relax.

• Innervate most organs of the digestive, respiratory, and cardiovascular systems.

• Prevent inflammation throughout the body.

• Filter sensory input - 80-90% of the nerve fibers in the vagus are sensory, meaning they bring information from the organs and even other cranial nerves (of the head and neck) to the “non-thinking part of the brain.” Our cranial nerves are involved in our unconscious assessment of the safety of others in our environment.

• Influence our social communication (the focus of a recent post)