Burning mouth syndrome causes chronic burning pain in your mouth. The pain from burning mouth syndrome may affect your tongue, gums, lips, inside of your cheeks, roof of your mouth, or widespread areas of your whole mouth, according to the Mayo Clinic. The pain can be severe, as if you scalded your mouth. Unfortunately, the cause of this condition can't be determined, but treatment options are available, according to information provided at http://www.mayoclinic.com/health/burning-mouth-syndrome/DS00462.