Hoarseness is the most common symptom of laryngeal disorders, and the degree of hoarseness can vary greatly, from slightly thickened voice and lower pitch in the milder cases to obvious hoarseness in the heavier cases, and complete loss of voice in the severe cases. The common causes of hoarseness are as follows: a. Damage to the motor nerves governing the vocal cords 1. Damage to the laryngeal recurrent nerve is most common, such as neck trauma, thyroid surgery, malignant tumors of the thyroid gland, and malignant tumors of the cervical esophagus can cause damage to this nerve. 2. When the vagus nerve is damaged before issuing this branch of the laryngeal nerve, it will also damage the laryngeal nerve bundle within it, such as neck trauma, vagus nerve sheath tumor, nasopharyngeal cancer extending to the parapharyngeal nerve and invading the vagus nerve. Occasionally, damage to the supraglottic nerve may be caused by trauma, which may weaken the vocal cord tension and cause low tone. When laryngeal disease affects the vocal folds, it can cause damage to the nerve, weakening the vocal folds and causing low pitch. 1, congenital malformation 2, laryngeal inflammatory diseases, such as acute and chronic laryngitis, laryngeal combination, diphtheria, laryngeal syphilis. 3, Vocal cord polyps, nodules, cysts. 4, benign laryngeal tumor, laryngeal papilloma, fibroma, hemangioma 5, malignant laryngeal tumor 6, trauma affecting the vocal folds or cricoarytenoid joint 7, metabolic disease of the larynx, laryngeal amyloidosis III, hysterical hoarseness