Typically, there are no visual signs like discoloration that help the diagnosis.
Possible causes include nutritional deficiencies, chronic anxiety or depression, type 2 diabetes, menopause, oral disorders such as thrush or dry mouth, or damaged nerves (specifically, cranial nerves associated with taste).
One cause of burning mouth pain, which may be often misdiagnosed as burning mouth syndrome, is a contact sensitivity Type IV hypersensitivity in the oral tissues to common substances such as sodium lauryl sulfate, a surfactant commonly used in household products, cinnamon aldehyde or dental materials. There are now several toothpastes on the market specifically without sodium lauryl sulfate or other preservatives which have been found to be associated with sensitivities.
This condition appears more often in women, specifically women after menopause, than men. Pain typically is low or nonexistent in the morning and builds up over the course of the day.
Alpha-Lipoic Acid 600 to 800 mg administered daily in three or four doses has been found to reduce symptoms. Trials have been small, but alpha-lipoic acid may be an appropriate adjunctive treatment option.