The common causes of hoarseness are vocal cord polyps, vocal cord nodules, chronic laryngitis, acute laryngitis, vocal cord leukoplakia, laryngeal papilloma, laryngeal cancer, vocal cord paralysis, acid reflux laryngitis, etc. 1.Vocal cord polyps, vocal cord nodules, chronic laryngitis: Patients mostly have a history of excessive vocalization, for example, they often speak for a long time, shout loudly, cry for a long time, or have a history of habitual throat clearing and frequent stimulation by tobacco and alcohol. Chronic laryngitis and early vocal cord nodules hoarseness is intermittent, and hoarseness will appear only after a long time of vocalization, while vocal cord polyps and larger vocal cord nodules are persistent hoarseness. 2, accompanied by laryngeal pain, swallowing pain, appearing after a cold and fever, may be acute laryngitis. Severe laryngeal pain that does not heal for a long time, also consider the possibility of laryngeal nodules or malignant tumors. 3, vocal cord leukoplakia: patients usually have a long-term smoking history, and the main symptom is hoarseness, which gradually worsens, which is a precancerous lesion and needs to be paid high attention. 32 cases of vocal cord leukoplakia were followed up by me in 2000, and the cancer rate was higher in cases with moderate to severe atypical hyperplasia [1]. 4.Laryngeal papilloma is common in children with progressive hoarseness, voice loss when the tumor is large, and also laryngeal wheezing and dyspnea. 5. A hoarse voice with laryngeal obstruction, cough, blood in sputum, or a neck lump, and a long-term history of smoking and drinking, should alert the possibility of laryngeal cancer. 6.Vocal cord paralysis can also appear hoarseness, mainly mute. 7. Sudden loss of voice, or low as a whisper, but laughing and coughing can be completely normal, which may be hysterical hoarseness. At this time, laryngoscopy shows abnormal vocal fold inversion, but the vocal fold can be normal inversion after coughing. 8. Foreign body sensation in the larynx, accompanied by coughing, a voice that is easily tired, or a preference for food before bedtime, or frequent acid reflux and belching, may also be reflux laryngitis. Laryngoscopy must be performed to determine the cause of hoarseness. Laryngoscopy includes indirect laryngoscopy, electronic laryngoscopy and supported laryngoscopy, of which indirect laryngoscopy is the most commonly used method to examine the vocal folds. For patients with poorly exposed vocal folds, electronic laryngoscopy is needed to show the laryngeal structures and lesions more clearly, and supported laryngoscopy can be considered for those who need to perform biopsy.