Often feel dry mouth may be the occurrence of the following conditions: First, the formation of stones in the salivary glands or produce foreign bodies blocking the ducts, resulting in the glandular secretion of liquid can not be discharged into the mouth, the lack of saliva lubrication after the oral mucosa dry; Second, the body immunity decline endocrine changes, resulting in Schegren’s syndrome when the glandular cells of the salivary glands are damaged, the volume of serious atrophy, the amount of secreted liquid significantly Reduced, the oral mucosa gradually dry cracking produce burning pain, can often contain acidic substances, stimulate gland secretion; Third, can not be timely replenishment of water, such as excessive exercise, sweat discharge more, or work busy, drink less water should be regularly replenished.