In recent years, the efficacy of treatment for nasopharyngeal cancer has been significantly improved due to the advancement of radiation therapy and the application of intensity-modulated radiotherapy techniques. Not only that, the complications and sequelae caused by radiotherapy have been reduced and alleviated accordingly, and the side effects are different from those in the previous conventional radiotherapy era. The main complications caused by intensity radiation therapy are as follows. First, dry mouth. Because the parotid and submandibular glands, which are responsible for the secretion of saliva, are near the target area of radiotherapy during radiotherapy, they are inevitably irradiated, resulting in the atrophy of these glands and a significant decrease in the secretion of saliva, which leads to dry mouth. However, the degree of dry mouth caused by intensity-modulated radiotherapy is significantly less than before, and the vast majority of patients do not need to drink water at night. At present, there is no good treatment for dry mouth, and most of the patients will have their dry mouth reduced after one to two years. Second, tinnitus, ear closure, hearing loss. There are mainly the following reasons: 1. Tumor invasion of the eustachian tube, as well as radiation therapy caused by adhesion of the eustachian tube, middle ear secretions can not be discharged from the eustachian tube, causing plasmacytoid otitis media, abnormal sound conduction, resulting in hearing loss. 2.Patients with apical bone invasion, the radiotherapy area is close to the inner ear, and radiation causes inner ear damage. 3.During radiotherapy, cisplatin chemotherapy is used, and cisplatin has the side effect of auditory nerve damage. The above factors can lead to the complications of tinnitus, ear closure, and hearing loss in patients after the end of radiotherapy. The treatment is firstly preventive. The dose to the inner ear during radiotherapy is controlled as much as possible in a safe range, and in case of plagiocephalic otitis media, tube drainage can be performed. Some patients with infections also need to be treated with antibiotics. Third, rhinitis and sinusitis. The main manifestations are nasal congestion, increased secretion and headache. Part of the nasal cavity and sinuses are the target area of radiotherapy. After being irradiated by radiation, the cilia on the mucous membrane of the sinuses and nasal cavity are damaged, and the cilia can discharge the secretions by swinging, so the secretions cannot be discharged normally after radiotherapy, and coupled with the decrease of local resistance, it is easy to complicate rhinitis and sinusitis. To deal with this, we should insist on nasal rinsing, use myrtle oil and other drugs to promote the discharge of secretions, use some local lubricating and anti-inflammatory nasal drops, avoid getting cold, and wear a mask when the air quality is poor and dusty. Fourth, radioactive brain injury. For patients with large local lesions, invading the cavernous sinus, temporal lobe and slope, the temporal lobe, brainstem, optic nerve and optic cross are inevitably irradiated during radiotherapy, which may complicate the injury of related areas in the distant future and appear the corresponding clinical manifestations. This situation should be prevented by reducing the volume and dose of irradiation to the neurobrain tissue as much as possible while ensuring the dose to the tumor area. Fifth, subcutaneous edema of head and neck. Due to the occlusion of lymphatic channels in the face and neck tissues after irradiation, and deep capillary edema, resulting in poor drainage in the tissue interstices of the face and neck, which leads to edema. It usually starts to appear 1-3 months after radiotherapy, is most serious in 3-6 months, and disappears in about half a year to a year, which has no effect on the body and does not require special treatment. Sixth, soft tissue infection. After radiotherapy, because local lymphocytes are removed by radiotherapy, blood vessels are occluded and blood supply is poor, as well as lymphatic vessels are occluded and drainage is not smooth, a small number of patients can appear cellulitis, which is manifested as redness, swelling and heat pain in the local area of the neck. This is the time to actively deal with it and adapt antibiotics for anti-infective treatment as soon as possible. The above several complications, compared with the previous era of two-dimensional radiotherapy, the incidence and severity, are significantly reduced. There are other complications, such as difficulty in opening mouth, neck fibrosis and dental caries, which have become very rare in the era of intensity-modulated radiotherapy.