Hoarseness is a common symptom in otolaryngology clinics and is most often seen in adults, especially young adults, but can also develop in children. Temporary hoarseness can also occur during upper respiratory tract infections and is often overlooked. However, hoarseness can sometimes be an early manifestation of a serious lesion and can be carefully examined and closely observed by indirect laryngoscopy, electronic laryngoscopy, or direct laryngoscopy, and treated accordingly. The common causes of hoarseness are: ① Acute and chronic inflammation of the larynx: the most common disease causing hoarseness. ②Vocal fold polyp: It is a common cause of hoarseness, and its onset is related to occupation, and it is common in those who speak more, such as teachers. ③Benign tumors: such as papilloma, fibroma, amyloidosis, chondrosarcoma, etc. ④Malignant tumors: those who are 45 years old or older and have hoarseness for more than 3 weeks should be alerted and examined carefully to avoid missing the diagnosis. (⑤) Recurrent laryngeal nerve paralysis: viral infection, trauma, and tumor compression can cause it. (6) Other causes: laryngeal trauma, congenital malformation, hysterical hoarseness, vocal fold groove, etc. Treatment of hoarseness: In addition to different treatments for different causes, such as anti-inflammation, necessary surgery (vocal fold polyp removal, laryngeal cancer radical surgery, etc.) or treatment of related diseases, we can also choose adjuvant treatments such as vocal abstinence, nebulized inhalation, physiotherapy and drug closure according to different causes. In addition, we should pay attention to vocal hygiene, living hygiene and environmental hygiene, such as avoiding loud shouting, staying up late, spicy food, environmental pollution and noise pollution, as well as appropriate vocal training. For benign lesions such as vocal fold nodules and vocal fold polyps, laryngoscopic removal can be performed on an outpatient basis, while larger polyps and laryngeal papillomas need to be removed by laryngoscopic support in hospital, and malignant diseases such as laryngeal cancer need to be treated by inpatient surgery.