## TL;DR

Stress is the body's response to perceived threats. Acute stress (fight-or-flight) is adaptive; chronic stress damages health (cardiovascular, immune, mental). Management: exercise, mindfulness/meditation, social connection, time in nature, deep breathing, therapy (CBT). Zebras don't get ulcers because they turn stress responses off.

## Core Explanation

Cortisol: chronic elevation from chronic stress damages hippocampus (memory), suppresses immune function, increases abdominal fat. HPA axis: hypothalamus → pituitary → adrenal — stress hormone pathway. Breathing: 4-7-8 technique (inhale 4s, hold 7s, exhale 8s) activates parasympathetic nervous system. Mindfulness: non-judgmental present-moment awareness — 8 weeks MBSR reduces anxiety by ~40%.

## Further Reading

- [Why Zebras Don't Get Ulcers (Robert Sapolsky, 3rd Ed)](https://us.macmillan.com/books/9780805073690/whyzebrasdontgetulcers)