What would cause the throat, tongue and mouth to burn? tests on heart have been done, heart is fine. many medicines for gerd they don't help.

Dry mouth?: If your nose is congested & you breath through your mouth, it can cause dryness of mucus mabrane of the mouth leading to pain & burning, keep your mouth moist with frequent sips of water, use saline nasal spray or gel to clear your nose especially at night. I hope that helps. Good luck

Burning Mouth: Syndrome is something dentists are trained to help you with. Since it would seem you have ruled out other systemic problems (heart & GERD) you should talk to your dentist who may be able to identify a medication you take now that causes it or detect a fungal problem which is the most common reason for burning mouth and find solutions.