Sputum includes saliva and phlegm. In medicine, sputum refers to coughing out from the trachea or lungs. The reasons why esophageal cancer patients keep spitting up are as follows: 1. Esophageal cancer will block the esophagus when it develops to a certain period, so it will be difficult for solid food to pass, and it will be more difficult for semi-liquid food and fluid food to flow down, so the saliva cannot flow down and can only be spit out through the mouth continuously; 2. Esophageal cancer will destroy the linguopharyngeal nerves and make these nerves fail, so the swallowing action will The swallowing action will be affected and saliva will be spit out; 3. When esophageal cancer develops to a certain stage, it will produce esophageal tracheal fistula, and the water in the esophagus will flow into the lungs causing lung inflammation. Therefore, patients who spit or spit up should be examined carefully.