Oh my, oh my, oh my.
This is not how a proper differential diagnosis is done. A differential diagnosis rather follows a "rinse and repeat" pattern:
- First, the doctor needs to get an overview of symptoms.
- The she/he needs to consider the symptoms and think about what it might be, or might not be.
- The doctor should then have list of a few diseases that could be it.
- On that basis it may make sense to order one or the other test – it makes most definitely no sense to order tests for thousands of Dollars/Euros/Pounds
- Taking into account the test-results and the symptoms, the doctor gets a preliminary diagnosis, based on which treatment can be chosen.
- If there are signs that the diagnosis is not the correct one, some (or all) of the steps above need to be repeated.
I for an example did not put enough value into my skin symptoms. Turns out the aphthous ulcers I had (together with other skin symptoms) are a key sign for Behçet's – and there is no blood test (or otherwise) for Behçet's. The only thing a doctor can do is carefully make note of all the symptoms, and knowing to look up the diagnosis of Behçet's.
Blood tests alone are a waste of money, especially if a doctor orders lots of them.
If you have ME/CFS, don't spend large amounts of money on tests – you need the money, I'm certain.
If your doctor wants to extract $$$$$ from you for diagnosis, tests or treatments: Change your doctor. Even if he claims that the tests or the treatments are a bargain. Especially if he wants thousands of bucks from you for tests and claims it is a bargain. And especially if he does the tests in an lab that is closely associated with her/him.
My advise: If a doctor sees you as a walking ATM, then change this doctor, because she/he is bad for you and your health.
There are some tests that might be called for, e.g. tests for hypothyroidism, BUT THE WORTHWHILE TESTS ARE PAID FOR BY THE INSURANCE. There are some test that might be "interesting" (like the NK-cell function test), but they do nothing to help you get "more legit" as a patient, or to choose a better therapy.
And just because someone is "Anti-CBT" or "Anti-GET", that does not mean he knows what he does.