Migration is a dynamic cultural, mental, behavioural, and physiological process and a disruptive life event. Migration may be a response to local stressors, but it also elicits physiological responses that can affect the current and long-term health and well-being of migrants. The final decision to migrate is complex and not made lightly. Often, migration is driven by insecurity, either in the individual’s household, their sending community, or broader economic, political, and social patterns and changes (Cohen and Sirkeci 2011; Crews et al. 2019). Stressors, uncertainty, and social conflict continue to plague migrants as they travel to their new, but perhaps not final, destinations, react to unanticipated challenges during their sojourns, and settle into a new society.

The insecurity and uncertainty associated with migration produce unique stressors with profound implications for the health of migrants. Insecurity may not always act as a main driver of migration (see Cohen and Sirkeci 2011: 97). However, migration can generate cognitive dissonance between expectations and actual circumstances; this generates uncertainty regarding how to protect one’s mental, social, and physical well-being (see Peters and McEwen 2015). Such cognitive uncertainty elicits a physiological stress response (allostasis). When chronically activated, allostasis can damage internal regulatory systems and result in poor health outcomes later in life (Peters et al. 2017). Chronic exposure to migration-associated stressors may result in physiological dysregulation–an allostatic load wherein immune, metabolic, cardiovascular, and neuroendocrine systems accumulate stressors and age-related damage (McEwen 1998). Cumulative wear and tear on these systems (allostatic load) is significantly associated with future and current chronic disease, declines in cognitive and physical performance, and mortality across multiple samples from different populations (Crews et al. 2012; Gruenewald et al. 2012; Karlamangla et al. 2002, 2006; Kusano et al. 2016; Seeman et al. 2001; Theall et al. 2012).