The esophagus is the tube that connects the stomach to the pharynx and is about 25-30 cm long. Cancer occurring in the esophagus is called esophageal cancer, which is one of the most common malignant tumors. Its occurrence is often related to diet, smoking, alcohol abuse, chronic inflammation of the esophagus, genetics, etc. The incidence increases with age above 30 years old, with a peak incidence between 50 and 69 years old. There are more men than women. So, how to detect esophageal cancer in early stage? 1.Foreign body sensation in esophagus: Usually, it feels like something is attached to the wall of esophagus and cannot be swallowed. 2.Choking sensation in esophagus: When eating, especially when eating dry food. Sometimes it seems like there is incomplete food in the esophagus, so the patient likes to make swallowing movements. 3.Post-sternal discomfort or pain: Patients always feel painful positioning behind the sternum when swallowing water or swallowing food, and this feeling gradually disappears after swallowing. 4, dryness and tightness in the throat: may be accompanied by mild pain, often associated with mood swings. 5.Vomiting after eating: Vomiting is often caused by eating, and the vomit is a large amount of mucus and food. 6, late symptoms: malnutrition, weight loss, respiratory distress, etc. may occur. Cytological examination: This examination is one of the desirable methods to diagnose early esophageal cancer. The detection rate can reach 80%. 1.Esophagoscopy: It is one of the more reliable methods to diagnose esophageal cancer. It can understand the location, nature and scope of lesion. 2.X-ray barium esophagogram: It is the main method to diagnose esophageal cancer. It can detect mucosal interruption, lumen filling defect and stenosis and soft tissue mass.