It's dismissive if the cause is not actually anxiety. Your entire argument only works if you accept the premise that this condition stems from anxiety alone.

It's dismissive if the cause is not actually anxiety. Your entire argument only works if you accept the premise that this condition stems from anxiety alone. Since you have accepted this with what appears to be near certainty, then of course the rest of your argument makes sense to you, and your diagnosis of anxiety probably feels compassionate and sensitive. To a person who does not share your confidence that anxiety is the only factor in play here, your dismissal of other possible factors is crazy-making. Just acknowledging that there might be a factor here we don't fully understand would be enough. It's fine if anxiety is the best diagnosis and treatment plan given what we know right now. But the certainty that it's the entire story is off-putting. You said yourself that depression/anxiety for physical symptoms are "diagnoses of exclusion, coming long after everything else has been exhausted." They are a fallback when you don't have another explanation. So why do you present a fallback diagnosis with certainty?