Vagal Tone

Health is framed as the ability to transition between nervous system states rather than staying only parasympathetic. Good vagal tone means the body can shift appropriately between sympathetic and parasympathetic states. Vagal tone is relevant to recovery because it has anti-inflammatory effects via the cholinergic anti-inflammatory pathway. Acetylcholine released at the splenic nerve terminus can reduce macrophage pro-inflammatory cytokine production. Reduced preoperative HRV may be linked to complications through reduced vagal anti-inflammatory capacity. Poor vagal tone makes it difficult for the body to exit fight-or-flight efficiently. Chronic sympathetic dominance suppresses digestion and increases systemic inflammation. Poor vagal tone can be caused by gut imbalances, intestinal permeability, dysbiosis, and unaddressed trauma.