There is always white mucus in the mouth may be normal saliva, dry mouth, thrush and so on. 1. Normal saliva is colorless mucus, but the mucosal epithelium metabolized by the oral mucosa may be in the saliva and look like white mucus. This generally need not be ignored. 2. Dry mouth: too little saliva secretion, resulting in increased salivary viscosity. Dry mouth may mainly be physiological dry mouth, and pathologic dry mouth includes dry syndrome, diabetes, hyperthyroidism, etc. 3. Thrush is a common candida infection in infants and young children, and white mucus may be present. White mucus in the mouth may also have other pathological factors, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.