In the early stages, symptoms are often not obvious, but there may be varying degrees of discomfort when swallowing coarse, hard food, including a choking sensation of swallowing food and burning, pinching or pulling pain behind the sternum. Food passes slowly and there is a sensation of stagnation or foreign body. The choking sensation is often relieved by swallowing water and disappears. The symptoms are sometimes mild and sometimes severe, and progress slowly. The typical symptom of middle and late stage esophageal cancer is progressive dysphagia. Firstly, it is difficult to swallow dry food, then semi-liquid, and finally water and saliva cannot be swallowed. Often spit mucus-like sputum, which is the secretion of saliva and esophagus in the lower throat. The patient gradually loses weight, becomes dehydrated and weak. Persistent chest pain or back pain indicates advanced symptoms, and the cancer has invaded the extraesophageal tissues. When the inflammatory edema caused by cancer obstruction temporarily subsides or part of the cancer is detached, the obstructive symptoms can be temporarily reduced, which is often mistaken for improvement of the disease. If the cancer invades the recurrent laryngeal nerve, hoarseness may appear; if it compresses the cervical sympathetic ganglion, Horner’s syndrome may arise. If it invades the trachea or bronchus, it may form esophageal, tracheal or bronchial fistula and cause violent choking and coughing when swallowing water or food, and respiratory system infection. The latter can also sometimes be caused by reflux of the contents of the esophagus into the respiratory tract due to obstruction. Finally, a cachectic state may develop. If there are liver and brain metastases, jaundice, ascites, coma and other states may occur. During physical examination, special attention should be paid to the presence of enlarged lymph nodes on the clavicle, liver masses and signs of distant metastases such as ascites and pleural fluid.