Much of the frustration patients feel arises from the ambiguity of the syndrome and what causes it.
"There is a group of problems that cause the mouth to burn... and then there is this term the burning mouth syndrome, which is what you have when you can't find anything else that could cause the symptoms," said Dr. J. Dale Browne, professor and chairman at the department of otolaryngology at Wake Forest University.
Several things can lead to this oral burning sensation; oral bacteria and yeast infections, orthodontia or dental work, cigarette and alcohol use, and certain diseases such as diabetes and hypothyroidism can cause dry mouth and burning sensations. Doctors also note that vitamin B deficiency can trigger the sensation.
But real burning mouth syndrome is different, as experts believe the chronic pain is tied to the brain, as well as the nerves that control the tongue and mouth.
Changing this neurological problem isn't easy, but treatments do exist. Dr. Allen Brewer, an anesthesiologist at University of Colorado Denver, treats patients by embedding a small electrode near the affected nerve. This electrode stimulates the nerve and effectively 'masks' the pain message sent by the nerve to the brain. According to Brewer, patients have had success with this method 60 to 70 percent of the time.
But while some of those with burning mouth syndrome may find relief from doctors' treatments, others go without any real hope of a cure. Many also lack a cohesive community to discuss their issues.
"There is no community for me -- I wish that there were," said Upah. "The only people I can talk to about it are doctors, and some of them have just given up on me.
"One said to me 'I can't be of any help to you' and showed me the door."