I've always found it a little strange when the doctor (or nurse) asks you, "On a scale of 0 to 10, how much pain are you in?"
Because pain (like many emotions) is relative to our understanding of it.
To me, when someone says a 10 for pain, I think of someone under the most excruciating pain--like when someone, G-d forbid, is being tortured.
However, someone else may think of 10 as just being really sick and uncomfortable.
That's why I like this graphic that is used to level-set what each number in the scale represents.
Using this simple graphic, our definition of pain is not purely subjective, but rather each person can look at the faces and expressions and see how they relate to them.
Of course, the goal on the right for zero pain is a great goal, even if not always achievable.
In a sense this is a very basic personal architecture--where you have your "as-is" on the scale and your "to-be" which is your goal.
Then the doctor and patient work together to figure out a transition plan on how to get there (medicine, rehabilitation, healthier living, etc.).
While pain is usually just a symptom, it is a beginning to get at the root cause of what is bothering us and needs to be fixed. ;-)
(Source Photo: Andy Blumenthal)