The main features of achalasia are: lack of peristalsis, increased pressure in the lower esophageal sphincter (LES) and a reduced relaxation response to swallowing movements. In layman’s terms, this means that the food swallowed into the esophagus cannot be transported efficiently and smoothly down the esophagus with the help of the esophagus (lack of peristalsis or diffuse pressure increase in the body of the esophagus), and that the gates of the stomach (lower esophageal sphincter and cardia) do not open smoothly during swallowing. Both of these conditions cause the food to remain in the esophagus instead of entering the stomach through the esophagus smoothly. Typical clinical manifestations are dysphagia, food reflux (regurgitation and, in severe cases, vomiting) and discomfort or pain behind the lower sternum. Specific etiology: The specific etiology of achalasia of the cardia is still unclear. It is generally believed that the disease is due to degeneration, reduction or absence of ganglia within the esophageal musculature and loss of normal propulsion of the esophagus. The lower esophageal sphincter cannot relax, resulting in food being retained in the esophagus. As time goes on, the esophagus gradually dilates, the wall becomes thickened, elongated, bent and loses muscle tone. The food retained in the esophagus is chronically stimulated by changes such as fermentation, which leads to congestion, inflammation and erosion of the mucosa, and in severe cases, even bleeding and ulceration. After a long time, cancer may occur in a few patients. Main manifestations: chest pain, esophageal syndrome (dysphagia, painful swallowing, acid reflux, regurgitation, vomiting, etc.) and extraesophageal symptoms (such as chronic pulmonary bronchopathy and recurrent aspiration pneumonia caused by reflux of food retained in the esophagus into the lungs). 1. Dysphagia Painless dysphagia is the most common and earliest symptom to appear. It can be mild at first, with a feeling of fullness only after meals. Dysphagia is mostly intermittent, sometimes light and sometimes heavy, often triggered by mood swings, anger, apprehension, shock or eating too cold and spicy food and other irritants. If the symptoms are mild, the patient can eat continuously, with a feeling of blockage behind the sternum, prolonged eating, no regurgitation, and no impact on the amount of food eaten. In severe cases, it is difficult to enter both liquid and dry diet. When the esophagus is extremely dilated, a large amount of food and mucus is often stored, and the swallowing difficulty is improved instead. 2, pain about half of the patients, often occurs after eating and cold drinks, drinking hot water can often relieve. The nature of chest pain varies, and can be boring, burning, stabbing pain, cutting pain or cone pain. The pain is mostly in the posterior sternum and upper middle abdomen, but also in the back of the chest, the right side of the chest, the right sternal margin and the left quarter rib area. The pain attacks sometimes resemble angina pectoris, and can even be relieved by sublingual nitroglycerin tablets. The causes of pain are: (1) food retention and dilatation of the esophagus, (2) a significant increase in the pressure of the LES (lower esophageal sphincter), and (3) a high amplitude isosynchronous contraction of the body of the esophagus. 3. Food reflux occurs mostly during or shortly after the patient eats, all of which are undigested food, often accompanied by nocturnal reflux. As the difficulty in swallowing worsens and the esophagus dilates further, a considerable amount of contents can be retained in the esophagus for several hours or days, and then reflux out when the position is changed. The contents of reflux from the esophagus do not have the characteristics of vomit in the stomach because they have not entered the gastric cavity, but they can be mixed with large amounts of mucus and saliva. In case of complications of esophagitis and esophageal ulcer, the reflux may contain blood. 4. Weight loss Weight loss is related to the difficulty in swallowing that affects the intake of food. For dysphagia, although patients mostly adopt methods such as choosing food, eating slowly, rinsing food down with more soup when eating or after eating, or straightening the chest and back after eating, breathing hard and deeply or rejecting air to assist the swallowing action, so that food can enter the stomach and ensure nutritional intake. The amount of long-lasting disease can still have weight loss, malnutrition and vitamin deficiency and other manifestations. 5. Airway symptoms Especially patients with nocturnal reflux are often accompanied by cough, coughing, shortness of breath and sleep snoring. Before going to bed, take the head low position to drain the contents of the esophagus, or drink a lot of water to facilitate the feeding of the esophageal contents into the stomach, ke to reduce the occurrence of symptoms. 6. Other Bleeding and anemia Patients may often have anemia and occasionally bleeding caused by esophagitis.