Day 1

What @Cactusflower said.

If "they can't find anything wrong" then you're dealing with the phenomenon that we still call TMS in honor of Dr Sarno. Details are irrelevant. You may also see the acronym MBS (mind body syndrome) and the updated one, PPD (psycho-physiological disorder). It's all the same thing.

Never forget that physical symptoms do not originate at the place we are experiencing the symptoms. The brain is in charge of every single symptom, sensation, and physiological process in our bodies. This is a neuroscientific fact.

The proof of this fact is in the phenomenon called Phantom Limb Pain, which is easy to look up. It's pretty fascinating if you know nothing about it. Doctors and scientists have accepted that Phantom Limb Pain is real pain, even though the body part where the pain is perceived no longer exists. Phantom Limb Pain is now treated with brain retraining, along with therapy for the psychological trauma that accompanied the physical loss of the limb.

The extension of this fact is what we find the most difficult to accept, which is that our brains are more than capable of creating sensations and symptoms for reasons of their own: which are psychological in origin, not physical.

Remember the mantra:
Specific symptoms are irrelevant.
Think psychologically, not physically.
Repeat.
And repeat again!