Vagus nerve

The vagus nerve is the tenth cranial nerve and a major component of the parasympathetic nervous system.

It extends from the brainstem to multiple organs, including the heart, lungs and digestive tract. In addition to regulating vital autonomic functions, the vagus nerve plays a key role in modulating inflammation through the cholinergic anti-inflammatory pathway.

In pain medicine, vagus nerve activity is highly relevant because low vagal tone is associated with chronic pain, stress and poor resilience. Stimulation of the vagus nerve — either through implanted devices or non-invasive techniques like auricular vagus nerve stimulation — can reduce pain perception, improve mood and calm inflammatory responses. The vagus nerve exemplifies the intimate connection between the nervous system, immune system and pain regulation.