Right subcostal pain may be caused by trauma, chest wall disease, liver disease, gallbladder disease, etc., and should be promptly consulted to find out the cause of the disease; dry mouth generally has little to do with the right subcostal pain, and dry mouth may be caused by low water intake or dry syndrome. 1. Right subcostal pain (1) Trauma: When external direct violence acts on the right subcostal area, it can lead to the injury of the skin, muscles and ribs in this area, thus causing pain. (2) Chest wall diseases: right subcostal pain may be related to intercostal neuritis, such as herpes zoster, spinal lesions compressing the intercostal nerves, or costochondritis. (3) Liver disease: the liver is near the right lower ribs, when the liver lesions such as hepatitis, it can cause pain in the right lower ribs, mostly hidden pain, and may be accompanied by jaundice, loss of appetite, nausea, vomiting and other digestive discomforts. (4) Gallbladder disease: common in cholecystitis, gallbladder stones, biliary ascariasis, etc., the gallbladder is located in the lower part of the liver, also in the lower part of the right rib cage, when the gallbladder lesions, it can cause pain in the lower part of the right rib cage, the pain is colic, and it can be attacked after satiety, overeating, drinking alcohol, eating greasy food and so on. 2. Dry mouth: if you drink very little water or eat food with more salt, dry mouth will appear, and the dry mouth symptoms will disappear after slowly replenishing water; if you suffer from immune system diseases, such as desiccation syndrome, drinking water can not alleviate dry mouth, and may be accompanied by dry eyes and other symptoms. If you have pain in the right side of the rib cage and drink little water because of the pain, you may also have dry mouth symptoms, so you should consult a doctor in time to clarify the cause of the disease and have the appropriate examination if necessary.