It is useful to understand that in general, such pain is not caused by the actions of of other people, though some sorts can be triggered by changes in the weather.
Usually, anyone who suffers chronic pain for any length of time knows how to treat it (my first choice is to treat it with contempt but ibuprofen is a good second option) and in general, the best thing you can do to help is to not worry too much about it. For the sufferer, it becomes part of the scenery -- an annoying part, it is true, but there it is and there's no point stopping to boggle every time you encounter it.
Yes, it's frustrating, but so's beating your head against the wall. In either case, the fix is the same.