Radiation therapy is a localized treatment, which simply means that where the irradiation is applied, the adverse effects will be produced. In terms of head and neck tumors, the most common discomfort is salivary glands, especially parotid glands, and dry mouth will appear about 2 weeks after irradiation, and it will gradually worsen; secondly, the sense of taste will be affected, which is a sign of loss of appetite due to tasteless diet or change of taste. The oral mucosa involved in the radiation will be congested and edematous one after another, and the secretion will form a thin white film on the surface of the mucosa, which radiotherapists call “white film”, and small ulcers will appear in serious cases. This process is difficult to avoid with the current radiation therapy technology, and the reaction will be worse if the radiation therapy is accompanied by chemotherapy, so patients should not be nervous. Damage to the salivary glands and taste buds is currently lacking in effective measures to mitigate, and radiation protection agents such as amifostine can improve this to some extent. As the oral mucosa is in a very fragile state, so in addition to avoiding irritating and overheated food, oral hygiene is extremely important. Patients are advised to rinse with alkaline mouthwash after each meal, which not only can reduce the bacterial infection in the oral cavity, but also is effective in preventing malnutrition and even tooth loss due to reduced saliva and gum recession after radiotherapy. The most common organs that cause discomfort after chest radiotherapy are the esophagus and the lungs and bronchi. After the esophagus is irradiated, it will cause a feeling of stagnation and choking when swallowing food, and in severe cases, pain when eating. A soft, crumb-free, moderately low-temperature, non-irritating diet can be taken to reduce damage to the esophageal mucosa, and vitamin B6 liquid plus gentamicin or some other anti-inflammatory Chinese preparations can be taken after meals to flush the esophagus and reduce the inflammatory response. In addition to intravenous fluids or a nasal feeding tube, an appropriate amount of surface anesthetics can be given before meals to reduce pain during feeding when severe esophagitis affects eating. The impact of lung and bronchus depends largely on whether the patient originally had chronic lung or bronchial disease. Avoiding colds and reducing secondary bacterial and viral infections during treatment are the main precautions, especially when leukocytes are reduced by timely use of leukopoietic drugs and prophylactic antibiotics when necessary. Upper abdominal tumor irradiation often causes nausea, vomiting and loss of appetite. These digestive system discomforts are mainly treated by corresponding symptoms, using gastro-dynamic drugs such as gastrofacial and morphine to reduce nausea, anti-diarrheal drugs to reduce diarrhea, and if necessary, fluids to reduce the water loss and electrolyte disorders caused by watery diarrhea. In addition to these site-specific discomforts, there are some common reactions to radiation therapy, such as erythema, dry peeling, and wet peeling of the skin at the irradiated site to varying degrees; hair loss at the irradiated site. The first step to reduce skin reactions is to keep dry, avoid scratching when itching is present, and there are now ointments to reduce skin reactions to radiation therapy that can reduce the incidence of wet peeling.