Xerostomia is a general term used to refer to dryness of oral mucosa, and is distinguished from a sense of thirst. Causes of xerostomia with a decrease in saliva which bears calcium metabolism such as recalcification of enamel canes include ; age-related atrophy of salivary gland, Sjögren's syndrome, salivary gland disorder due to radiation therapy, side effect of medication, and autonomic nervous system imbalance, dehydration. Xerostomia without decrease in saliva production but shows excessive evaporation of saliva could be due to mouth-breathing. Symptoms of xerostomia include ; burning sensation in the mouth, poor oral hygiene, inflammatory change of oral mucosa, high incidence of periodontal disease or caries, and impairment of oral function (dysphagia, dysgeusia, and speech disorder) . This article discusses about xerostomia and dysphagia.