It could be a tumor, or it could be demons

[TranquillityBase]

It could be a tumor or it could be demons,
your symptoms will still be the same.
Can't say which is worse, a malignance or mystery,        "a possession" ?
or which one is worse for the brain. 

Pale entrails in cauldrons, wild pine nuts divining,
or oracle bones cloaked in smoke,
would shame all the blood draws and blood sugar panels,     I know nothing about medicine, but I think something more invasive than a blood sugar test would be involved; "blood draws and MRIs"?
the blitheness of shrugging white coats.

They quibble insurance while specters still linger 
behind every negative test.
With questions unanswered and answers unquestioned,
we hold each breath tight to our chests.

I don't have much to suggest aside from the above; it's a strong poem and already seems pretty polished.  Last line left me puzzling why it's "we" and "our", but I have my guesses.

TqB