Dry mouth after smoking is generally caused by oral mucosal damage, endocrine dysfunction, weather factors or lack of moisture. 1. Oral mucosal damage: tobacco in the role of various substances, can cause stimulation of the oral mucosa so that dry mouth occurs, tobacco can also reduce oxygen tension, while easily lead to the occurrence of periodontal disease. 2. Endocrine dysfunction: Endocrine dysfunction is generally the pituitary gland’s secretion of various hormones too much or too little, causing dry mouth, dizziness and other symptoms. The irritating substances in cigarettes can cause endocrine disorders, leading to dry mouth. 3. Weather factors: Usually the weather is hot, which causes the body to perspire too much, thus causing the body to lack water and the phenomenon of dry mouth. 4. Lack of water: the patient may usually drink less water, resulting in a lack of water in the body, which causes the symptoms of dry mouth. There are many other causes of dry mouth after smoking, it is recommended to consult a doctor in a timely manner, under the guidance of the doctor to determine the treatment program, to avoid blindly using their own medication.