Peter, that's really not what I need at all. These are more like relationships than they are tags/categories IMO.
With your suggestion, you would need to make a tag/category for EVERY service page (of which there are 150+), and tag each condition (over 500) as that.
Services don't all have the same treated condition, each one has a unique set of them. In addition to that we use a right to left relationship query to find related service to display on each condition page. Relationships seems more likely to be used in this scenario. Perhaps I explained it poorly in the first post.