A very dry and rough tongue may be caused by dietary factors, medications, candida infections, dry syndrome and other reasons. 1. Dietary factors: Usually, patients who eat salty food or do not drink enough water may cause symptoms of dry mouth, accompanied by a dry and rough tongue. 2. Drugs: patients taking some drugs, may also cause dry mouth phenomenon, the general instructions of the drug will also point out that it may lead to the tongue is very dry and rough, such as brompropylaminotriptyline and other anticholinergic drugs. 3. Candida infection: generally caused by a variety of pathogenic Candida fungal infectious diseases, it can cause symptoms of dry tongue, accompanied by burning pain in the tongue. 4. Dry syndrome: a chronic inflammatory autoimmune disease characterized by decreased secretion of the lacrimal and salivary glands, patients may also experience dry tongue. There may be other reasons for a dry and rough tongue, so we recommend that patients actively seek medical attention to clarify the cause of the disease and then undergo regular treatment.