Mannitol is a commonly used dehydration agent in clinical practice, which has a good dehydrating effect and can effectively improve the phenomenon of body edema. It is normal to experience pain during intravenous administration of mannitol, which is mainly due to the fact that mannitol produces strong irritation to the muscles, thus leading to the appearance of pain. Clinical for the relief of this symptom has the following suggestions: First, in the injection, the speed is as slow as possible, you can apply hot compresses around it, which has a good effect on the relief of pain; Second, try to elevate the upper arm after the injection, which can promote the return of blood to the veins to avoid the phenomenon of phlebitis; Third, for the patients with more serious pain phenomenon, you can wipe the safflower oil to promote blood circulation and reduce the pain. blood circulation and reduce the pain. Patients at this time should pay more attention to rest, avoid strenuous exercise, maintain physical and mental pleasure, avoid excessive anxiety and tension. Diet can eat more nutritious food, as well as fresh fruits and vegetables, for pain relief is also helpful.