Neurophysiological mechanisms of breathing-based well-being practices: a narrative review for clinical application

Breathing is a physiological process that extends beyond gas exchange, linking neural, cardiovascular, glymphatic, and autonomic systems. This narrative review summarizes how breathing-based practices modulate physiological processes in the body and brain, emphasizing their applicability in clinical care. Regulating the pace and depth of breathing, particularly with relaxed exhalation, may engage vagal pathways that lower heart rate and blood pressure and promote a shift toward increased parasympathetic tone relative to sympathetic activity. Neuroimaging studies show that controlled breathing reduces activity in stress-related brain regions while enhancing networks supporting calm attention and emotional steadiness. Changes in breathing depth also influence cerebrospinal fluid movement, though direct evidence of waste clearance in humans is lacking. This review identifies populations requiring caution, including individuals with panic symptoms, significant cardiopulmonary disease, or pregnancy. Clinicians should distinguish between breathing-only and multimodal protocols when interpreting research findings, as combined interventions preclude attribution of benefit to breathing alone. Study design quality, particularly the use of active rather than waitlist controls, should inform how effect sizes are interpreted. Breathing practices are not a replacement for medical treatment but may represent accessible, low-cost adjuncts for stress reduction and cardiovascular regulation.