Radiation esophagitis (RE) is an adverse reaction to radiotherapy for thoracic malignancies and a major factor limiting the dosage for thoracic tumors. In cases of RE, mild conditions may involve only discomfort in the throat, severe cases can present with intense pain and significant difficulty swallowing, and may lead to interruptions in radiation therapy, affecting the treatment outcome. However, much of the current research focuses on how to diagnose and treat the disease and needs to address the prevention of RE. In this review, several online databases, including PubMed, Web of Science, Google Scholar, the China National Knowledge Infrastructure, and the Chinese Medical Journal Database, were searched to collect relevant published studies. This review provides updated information on the pathogenesis, diagnosis, risk factors, development of predictive models, prevention, and treatment of RE, aiming to serve as a reference for its diagnosis, treatment, and prevention.