Mental stress has always had its physical component. In fact, that's what the stress response is: the visceral priming of the body to either fight or run away from a perceived danger. Less well recognized is that even chronic, unpleasant stress, the kind that's so constant you consider it normal, can cause aches and pains that you might not attribute to emotions. By some estimates, half of the patients doctors see for various common body aches are actually expressing psychological distress through physical pain.

The source of stress-related pain lies in the brain, which, when you feel under the gun, triggers the release of cortisol, adrenaline and other hormones that prepare the body for action by, for example, increasing heart rate, blood pressure and respiration. Less noticeably, these hormones also make muscles tense up, which can cause aches and irritate nerves.

Here's a guide to the areas stress hits most often, and simple steps you can take to relieve the pain.