Cranial nerve damage is often the earliest invasion of the tongue muscle, with atrophy of the tongue muscle, accompanied by tremors, later the palate, pharynx, larynx muscle, masticatory muscles, etc. also gradually atrophy and weakness, so that the patient dysarthria, swallowing difficulties, chewing weakness, etc.. Ball palsy can be the first symptom or appear after limb atrophy. Atrophy of tongue muscle can also be seen in nasopharyngeal carcinoma. Prevention: 1. Control the condition of nasopharyngeal carcinoma. Prevent direct invasion or lymph node metastasis to the posterior region of the caudate or the sublingual nerve canal. 2. Avoid cranial nerve damage. It causes deficiency of both qi and fluid of the stomach and kidney and loss of nourishment of the tendons and veins of the tongue. Tongue impotence and softness while the tongue is dry and vivid without fluid is a sign that kidney yang has been deficient to the extreme and the condition is sinister. It is recommended to actively treat the primary disease, or try Chinese herbal medicine to regulate and diagnose and prescribe dialectical treatment.