In a conversation with Sigrid Ellis, the topic of the traditional "how bad is the pain, on a scale from 1 to 10" doctor's office/hospital question came up, as did its flaws. Sigrid said something and gave me permission to publish it here:

Pain scales are particularly useless for chronic pain .... "I think about my pain constantly" is a 4, "my pain interferes with my daily tasks" is a 7, but if I tell doctors that my pain is at a 7 while also conversing normally and smiling and joking, they assume I am either exaggerating, lying, or that I don't understand the scale. It's only good for acute pain, if it's good at all.

For chronic pain I think a more useful scale would be as follows:

0: I am heavily and effectively medicated to the point that my chronic pain is not noticeable.

1: I am medicated to the point that I feel able to do activities I cannot do under my usual medication regime.

2: I am medicated to the point that I can do additional normally medicated tasks.

3: My pain levels are at the level accomplished by my usual daily medications. I can do my normal daily tasks, but not anything more.

4: I am taking my normal medications, but my pain levels are not adequately controlled. I cannot do all of my normal tasks. However, this doesn't hurt enough to justify additional medication because this state happens too often and I can't afford - medically, emotionally, economically, etc. - to waste the additional meds for something this minor.

5: My pain is breaking through normal daily meds and I am taking additional meds for breakthrough pain. I may be able to conduct my daily tasks or even additional tasks, depending on the side effects of my breakthrough meds.

6: My pain is not controlled by breakthrough pain medication. I cannot perform all of my daily tasks, but I can do most of them through the pain.

7: My pain is not controlled by breakthrough medication. I cannot do all of my daily tasks. Some things will be skipped or dropped or given to others.

8: My pain is not controlled by breakthrough meds. I can barely accomplish any of my daily tasks or self-care. I may not shower or cook or get out of bed. If I have emergency pain management meds, I might take them at this point.

9: I need to take emergency pain medication if I have any. I will probably be unable to perform daily tasks or self-care due to the nature of emergency pain management medications. My pain may or may not be controlled by all of my meds.

10: Nothing controls or mitigates this pain. Not daily, breakthrough, or emergency medications. I cannot do any daily tasks.

..... The only purpose of a pain scale at all, in my opinion, is to convey information to other people in a format they will respond to. .....

Particularly with pain scales, I know how my pain feels to me. The point where "how I feel" impacts "what I can do" is the point where my feelings start to become visible to others. Either because I am in visible distress or because my functionality is impaired. At that point, a scale indicating in what manner my functionality is impaired and what I need other people to either do for me or how they should modify their expectations is the important point.
With chronic pain, the amount of ongoing medication I would require to be pain free on a daily basis would rapidly become life threatening due to the addictive nature of pain medication. What I want from my pain management is to hover around 2-4, with options for achieving 1 on some special days and never staying past 8 on my very worst days.
I want daily medication to keep me in 2-4, breakthrough meds that bring me back to a 3 or 4 when I hit a 6 or 7, and emergency meds that will give me relief if not functionality on rare bad days.

That's what I want doctors to understand.

I appreciated getting Sigrid's perspective and figured you might too.

Many of us have learned to translate our concerns into words like "interferes with work" or "keeps me home from my job" or "can't do normal activities" with doctors, who have jargon like "activities of daily living" on checklists to check. (And to say "my friend had this problem and [thing] helped; would it help me?" rather than "I did some research and learned [thing] might help; could we try it?" because the former does not bother a doctor's sense of entitlement to deference regarding who gets input into diagnosis and treatment.) Here's hoping that, if you have chronic pain, Sigrid's formulation helps you think about your pain treatment and talk about it with your practitioners more effectively.