Here IS the first one:
http://painconsortium.nih.gov/pain_scales/index.html

There are many, many more?

When asked? I say right off the bat? 'I DO NOT 'DO' HAPPY FACES'! AT ALL!!
If they ask me for 'more detail'? I reply: Do you want me to bite you? Nuff said. No one's committed me yet!

There are many, many ways to describe PAIN... It's all subjective.
Do check out all the medical jargon for 'pain' to find the best analogies for YOUR PAIN.

Sometimes it's easy? Others more complicated. BUT? Whatever you do? Be consistent about how your pains 'feel' at first? And, if they change, document those changes as best you can...when they change!
Timing of 'events' and symptoms of those 'events' could lead docs off on either diagnosis or 'tangents'. But? If 'tangents'? These are things that can be later excluded from final diagnosis.. AKA 'One more off the list!'
Get even with this! Get your diagnosis and treatment! My heart is with you, I've been there shouting at empty walls on occasion. No one will answer.
I am hoping that you CAN and DO get help! And SOON! Hugs !'s and hope!!!!1 - j