Edema and congestion of the esophageal mucosa is caused by esophagitis. Esophagitis (esophagitis) is an inflammation of the esophageal mucosa caused by edema and congestion of the mucosa due to abnormal stimulation of the superficial or deep tissues of the esophagus. Differential diagnosis: 1. septic esophagitis: septic esophagitis is most commonly caused by mechanical injury from foreign bodies. Bacteria multiply in the esophageal wall, causing local inflammatory exudation, varying degrees of tissue necrosis and pus formation, and can also present as a more extensive cellulitis. 2. Esophageal tuberculosis: Patients with esophageal tuberculosis usually have the first symptoms of tuberculosis in other organs, especially pulmonary tuberculosis. Symptoms in the esophagus itself are often confused or masked by symptoms in other organs, so that they cannot be detected in time. According to the pathological process of tuberculosis, the early infiltrative progressive stage may have toxic symptoms such as malaise, hypothermia, and increased blood sedimentation, but there are also those with no obvious symptoms. This is followed by dysphagia and progressive dysphagia, often accompanied by persistent pain in the throat and retrosternal area, which is aggravated by swallowing. Ulcerated lesions are mostly characterized by pain on swallowing. Spillage of food into the trachea should be considered as the formation of tracheoesophageal fistula. Difficulty in swallowing suggests scar stenosis due to lesion fibrosis. 3, fungal esophagitis: the clinical symptoms of fungal esophagitis are not typical, and some patients may not have any clinical symptoms. Common symptoms are swallowing pain, dysphagia, epigastric discomfort, retrosternal pain and burning sensation. In severe cases, the retrosternal pain is cut-like and can radiate to the back, resembling angina pectoris. Severe bleeding can occur in Candida esophagitis but is uncommon. Untreated patients may have epithelial detachment, perforation, or even disseminated candidiasis. Esophageal perforation can cause mediastinitis, esophagotracheal fistula and esophageal stricture. Granulocytopenic patients with persistent high fever should be examined for disseminated acute candidiasis of the skin, liver and spleen, and lungs. 4. Viral esophagitis: HSV infection of the esophagus is often accompanied by nasolabial herpes. The main symptom is painful swallowing. The pain often intensifies when swallowing food, and the patient swallows and then the food goes down slowly in the esophagus. A small number of patients have dysphagia as the main symptom, and mild infections may be asymptomatic.