Edema and congestion of the esophageal mucosa is caused by esophagitis. Esophagitis (esophagitis) is an inflammation of the superficial or deep tissues of the esophageal mucosa due to abnormal irritation, resulting in edema and congestion of the esophageal mucosa. These stimuli include stomach acid, bile from duodenal regurgitation, strong alcohol, peppers, too hot vegetable soup, too hot tea, etc. It can be divided into primary and secondary esophagitis. There are many causes of esophageal inflammation; such as severe vomiting, long-term placement of nasogastric tube or aspirin, strong acid and alkali, non-steroidal anti-inflammatory drugs or chemotherapy, radiation therapy patients or patients with reduced resistance to tuberculosis or Candida or viral infection resulting in esophagitis. Examination methods: 1, fiberoptic endoscopy: The mucosa of the lower and middle esophagus is seen to be congested, edematous, with surface erosion and small shallow ulcers, sometimes with stenosis. 2.Barium esophageal meal examination: the peristalsis of the esophagus is weakened, the mucous membrane of the lower part of the esophagus is coarse and disorganized, and sometimes small niche shadows and strictures are visible. 3.Esophageal PH measurement: Determine the esophageal PH value and observe its reflux situation. If necessary, 24-hour esophageal PH monitoring test can be done to understand the circadian rhythm changes of esophageal PH. 4.Esophageal pressure measurement: When normal people are quiet, the lower esophageal sphincter has a certain pressure, and the pressure is reduced in patients with gastric and esophageal reflux. 5.Acid drip test: The acid drip test is used to stimulate the patient’s symptoms as one of the diagnostic methods. Under normal circumstances, stomach acid does not reflux into the esophagus. There is a high pressure area in the lower part of the esophagus that blocks the reflux of stomach acid into the esophagus, and if the cardia becomes loose for any reason, the pressure in the high pressure area will drop or even disappear, and stomach acid and bile will reflux into the esophagus, stimulating the esophageal mucosa strongly and triggering esophagitis. Lying flat after a meal, eating too much, eating too much sweet or greasy food can cause reflux from the stomach to the esophagus.