Hello,
This is likely to be from a Gastro-Esophegeal-Reflux Disease / Hiatus Hernia, that is pain caused by a reflux of stomach acid into the food pipe and thus the pain.
This pain would be in the center of the chest and would be exacerbated by sleeping on your side and while bending over.
This is unlikely from a Cardiac cause.
OTC Antacids like Pirlosec, taken twice a day 1/2 hour before meals should help with this pain.
Avoid bending over and sleep in a slightly propped up position.
If this still persists, please see a doctor for an evaluation and possibly a Barium Swallow X rayto look for a Hiatus Hernia.
Kind Regards, Dr.Joshi P.S. Please click *** ACCEPT *** if you are satisfied, otherwise I do not get paid for my work and JustAnswer holds your Deposit.
Doctor
Medical Diagnostics : X ray, CT Scan, MRI, Ultrasound, Angio. Caring Doctor. Your Health, First !