Chronic psychological stress

Chronic psychological stress is a sustained sense of threat or demand that keeps your stress system (the HPA axis) switched on. That means your cortisol stays high for long stretches. Acute stress is a brief spike; chronic stress is the elevated baseline. Over time, your immune cells grow resistant to cortisol's anti-inflammatory signal. So pro-inflammatory cytokines (IL-1β, IL-6, TNF-α) run unchecked, a state called inflammaging. Excess cortisol and reactive oxygen species also speed telomere shortening. A landmark study (Epel et al., 2004, PNAS) looked at 58 women (39 caregivers of chronically ill children, plus 19 controls). The most-stressed women had telomeres about 550 base pairs shorter, roughly a decade of extra biological aging, and 48% lower telomerase activity, than the least-stressed. And longer caregiving went with shorter telomeres. Other evidence links chronic stress to faster epigenetic clocks and higher death rates. But most studies are snapshots, and cause has not been proven in trials. So the HPA-telomere-inflammaging triad is a biologically plausible, well-supported mechanism of stress-driven health loss, not a fully proven causal chain.

Last reviewed: June 22, 2026

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