Neuroendocrine Correlates of Occupational Burnout and Chronic Stress in Secondary School Teachers: An Integrated Biomarker and Psychometric Study in Rancagua, Chile

Background: Chronic occupational stress reflects allostatic overload, dysregulating the HPA axis. Teacher burnout is usually assessed via self-report, overlooking biological correlates and subjective nuance. We used a mixed-methods design that integrated nail cortisol—a retrospective biomarker of chronic stress—with qualitative narratives. Methods: We conducted a convergent mixed study on secondary school teachers in Rancagua, Chile. We gathered nail cortisol and surveys (n=68; regression models adjusted for sex, hours, and climate) alongside 26 in-depth qualitative interviews coded across eight structural dimensions. Results: Contractual instability was the primary risk factor: teachers with ≤33h had higher clinical stress (75.0%) vs. full-time. Women showed greater stress than men (60.6% vs. 26.7%, p=0.012). Nail cortisol declined under chronic overload (β=−0.85), suggesting hypocortisolism. Qualitatively, distress emerged as an embodied phenomenon: affective-somatic symptoms, parental conflict, and classroom precarity act as triggers, with vocation sustaining work while driving overexertion. Conclusion: Chronic stress in teachers combines neuroendocrine dysregulation with an embodied, systemic toll tied to job insecurity.