The "Rate Your Pain" scale, interpreted in an infographic.

[full_metal_ox]

This has obvious application to illness and injury in modern-day settings; it may also be of real-life use to people who (like me) tend to be flummoxed by That Question: compared to what? On the scale of all the pain I've ever suffered? When I move it like this? Compared to that guy in the next waiting-room seat stoically nursing a hastily-bandaged stump?

http://web.archive.org/web/20150926095217/http://doodleloser.tumblr.com/image/129648278146

(3/31/16: longlivehumour has informed me that Doodleloser has deleted her Tumblr, and helpfully brought up an archived image; I've replaced the link accordingly.)

ETA: Something I ought to have anticipated: warning for graphic personal accounts of injury and illness in the comments.