There are many reasons for the dryness of voice six months after surgery for thyroid malignant tumor. Dryness of voice after surgery for thyroid malignant tumor is not a major complication, and after excluding other factors (such as acute and chronic laryngitis, pharyngitis, nasal diseases, and lifestyle habits), we will consider whether it is related to the history of thyroid surgery. Thyroid malignant tumors are usually operated with total or subtotal thyroidectomy, and the main complications are: 1) Hoarseness and change in timbre. Difficulty in breathing, even suffocation. Looseness of the vocal cords and decrease in pitch. Loss of laryngeal mucosal sensation, resulting in choking when eating. Some patients who refuse to drink water or drink less water due to choking on water may also show dryness of the throat. If there is no combination of the above symptoms, dry throat should first consider chronic pharyngitis, nasal diseases and other disease factors, dry throat is often seen in chronic pharyngolaryngitis, long-term inflammatory stimulation of the pharyngeal glands hyposecretion, glandular secretion is reduced. Some nasal diseases can also be due to nasal breathing and open-mouth breathing, resulting in the pharynx senseless evaporation of more water, there will also be a dry throat. Sometimes physical stimulation will also appear dry throat symptoms, such as eating spicy stimulating food, drinking too much, staying up all night and so on can also be induced, can drink more water in moderation to observe whether there is any improvement in the character. In addition, we should also consider the recurrence of tumor invading the trachea and other reasons. If the symptom persists, it is recommended to go to the hospital to improve the relevant examination under the guidance of professional physicians to make a clear diagnosis.