Mr. Zhang is 45 years old and has always been healthy. Half a year ago, Mr. Zhang suddenly developed hoarseness, and after laryngoscopy in the local hospital, no obvious abnormality was found. In the past week, he started coughing and coughing up sputum, and occasionally blood was seen in the sputum. He was admitted to the hospital and underwent a CT scan of the chest, which indicated that the left lower lung had occupational lesions and was considered to be lung cancer. It turned out that hissing half a year ago was a dangerous early signal. As we all know, the process of vocalization is complicated, and once the mediastinal lymph node enlargement occurs in patients with thoracic tumors, it is very easy to compress the recurrent laryngeal nerve in the thoracic route, resulting in the above symptoms. Clinically, hoarseness caused by enlarged left mediastinal lymph nodes is more common, which is mostly seen in left lung cancer or esophageal cancer with left mediastinal lymph node metastasis. Therefore, middle-aged and old people with unexplained hoarseness should be alerted and should not forget to take CT scan of chest for early exclusion of thoracic diseases along with detailed examination of larynx.