The side effects of radiotherapy are also directly related to the patient’s radiotherapy site, as follows: 1. systemic manifestations, which can be manifested as weakness, loss of appetite, lack of energy, etc.; 2. radiotherapy to the head, which can lead to hair loss, skin changes, redness, blackness or dizziness, headache, nausea, vomiting, etc.; 3. if radiotherapy to the esophagus is required, patients will also experience specific side effects, such as painful eating, coughing, coughing sputum, bone marrow suppression, white blood cell drop, which are all side effects caused by radiotherapy; 4. If patients need to receive abdominal irradiation, such as rectal cancer, liver cancer, stomach cancer and other diseases, the side effects mainly affect the function of the digestive tract, such as difficulty in eating. In conclusion, different clinical manifestations will occur in different parts of radiotherapy, and these clinical manifestations can be controlled accordingly by taking symptomatic treatment to ensure patients can complete radiotherapy successfully as much as possible, thus ensuring better clinical efficacy.