The main clinical symptoms of esophageal cancer are progressively aggravated with the development of cancerous foci. Early symptoms: (1) Hard choking sensation in swallowing food, which occurs occasionally without affecting eating. (2) Pain and discomfort at the back of sternum or upper abdomen, mostly accompanied by dysphagia. (3) Foreign body sensation in the esophagus, most of which is the discomfort of not being able to spit out or swallow. (4) Dryness and constriction in the throat. (5) Slow passage of food and feeling of retention. (2) Symptoms of middle and advanced esophageal cancer: (l) Progressive dysphagia: it is the most common and typical symptom, which represents the degree of narrowing and obstruction of esophageal lumen. (2) Vomiting mucus. (3) Chest and back or hypopharyngeal pain. (4) Metastatic symptoms and signs: ① neck mass; ② hoarseness; ③ compression symptoms: compression of cervical sympathetic nerve, compression of trachea and bronchus, invasion of septal nerve, invasion of vagus nerve compression of superior vena cava, invasion of pleura, spine, involvement of brachial plexus nerves, etc; (4) corresponding symptoms caused by metastasis to the liver, lungs, and brain. (5) Esophageal hemorrhage. (6) Esophageal perforation: esophagus and trachea or bronchus repeatedly, esophagus and aorta, esophagus and lung, esophagus and mediastinum healed, and so on.