Tell the doctor in charge of the HBOT unit. Mine was present in the room everyday, which was associated with wound management. The ache from lying in the tube for two hours seems plausible, but I'm no doctor or expert. I have periodic back problems in general, so I don't recall anything unusual, but last year, I thought I hurt my back, and side in the gym, and it turned out to be a kidney stone, so you never know. Good luck.
