Burning tongue syndrome is a collective name for diseases that cause a burning pain of the tongue, however, no clear clinical or laboratory abnormalities may be observed. The pain is a superficial, described as a burning sensation, and may occur in the tongue, palate, lips, buccal mucosa, gingiva, and teeth. Seventy-five percent of patients with burning tongue syndrome are middle aged women in their 50's and they are often post-menopausal. However, this syndrome may be observed in all ages regardless of gender. A variety of pathological causes have been proposed for this mysterious syndrome. Pain can be classified as nociceptive, neuropathic, or psychogenic, and the mechanism for the onset of burning tongue syndrome has been investigated in relation to all of these. Pain can be classified as acute or chronic. While acute pain may be alleviated with rest or analgesics, chronic pain lasts beyond a reasonable time needed for healing of an acute disease or wound and it may overlap with psychogenic pain. Many cases of burning tongue syndrome have been classified as chronic pain (psychogenic pain). Marked inflammation or tissue damage in burning tongue syndrome that are sufficient to account for the pain have not been detected. However, mild glossitis, micro-trauma caused by dentures, and dry mouth are often observed. Therefore, burning tongue syndrome may result from chronic pain caused by chronic irritation to the nociceptor in these minor lesions. In recent years, burning tongue syndrome has been proposed to be a neuropathic pain of the lingual nerve involving a taste disorder. Since the causes and background factors of burning tongue syndrome are not obvious, multiple treatments exist. The cases with dry mouth are treated with oral drugs such as pilocarpine hydrochloride, to promote salivation. For cases with taste disorder, zinc therapy using polaprezinc has been effective. For cases with suspected non-organic pain, anti-anxiety drugs or anti-epileptics, such as benzodiazepine, are recommended. The anti-epileptics, Rivotril® and Landsen®, enhance the GABA neuron activity specifically and are considered to be effective for neuropathic pain in burning tongue syndrome. For cases with masked depression, tetracyclic antidepressants or SSRIs are recommended. Patients with masked depression may have physical complaints and autonomous neurological symptoms, while the symptoms of depression are inconspicuous. Therefore, they have some common characteristics with patients with burning tongue syndrome.