This is a good time to keep a symptom diary, so you can see if something about your level is unbalanced FOR YOU. The ranges of normal are quite large, precisely because some patients feel normal at the high end, others at the low end. Keeping a detailed symptom diary can help you figure things out when things "seem" fine, yet may not be fine.
When one level is out of the normal range, it’s absolutely something that needs to be investigated. There may be several causes, and it may not be what you expect, especially if your "other" level seems normal. In any event, the discussion should continue. You and your doctor should talk about the possible next steps, whether it’s further tests, or changing your meds.
