If you’re stuck in a busy office or on an overcrowded train, you can’t run away, so you can’t use up the chemicals your own body makes to protect you.
Humans have inherited these things from our ancient ancestors, who needed to be able to either run away from danger or stay and fight. Once the pressure or threat has passed, your stress hormone levels usually return to normal. However, if you’re constantly under stress, these hormones remain in your body, leading to the symptoms of stress. If you’re stuck in a busy office or on an overcrowded train, you can’t run away, so you can’t use up the chemicals your own body makes to protect you. Over time, the build-up of these chemicals and the changes they produce can be damaging to your health.