It is common for brain tumor patients to develop cerebral edema, which makes the condition more difficult. Many patients need to treat cerebral edema before giving effective treatment, which delays the treatment of tumor. What are the causes of cerebral edema? 1. Pre-operative edema: the tumor pressurizes the surrounding brain tissue or obstructs the cerebral venous reflux, increases the venous pressure, intracranial stasis, impairs the absorption of cerebrospinal fluid circulation machine, as well as the biological toxicity of tumor, which affects the brain tissue around the tumor, damages or destroys the blood-brain barrier, increases the permeability of vascular wall, and produces limited cerebral edema. 2. Postoperative cerebral edema: The richer the blood supply and the larger the tumor is, the more veins are destroyed in the process of resection, and the degree of edema may be powerful after surgery. Moreover, due to the long-term compression of brain tissue by tumor, the perfusion pressure of brain tissue increases after removal of tumor, and postoperative reactive edema is heavier than other intracranial tumors. It is at the peak of cerebral edema 2 to 3 days after surgery. Patients with meningioma with high VEGF (vascular endothelial growth factor) content in immunohistochemistry will also have significant postoperative edema. 3. Radiation damage: For patients with brain tumors, another important cause of cerebral edema may be radiation damage, which is one of the side effects of radiotherapy for brain tumors. Firstly, mannitol and glycerol fructose are very commonly used. Mannitol is fast-acting, but it is harmful to kidney function, so it is recommended to review kidney function regularly; glycerol fructose is less harmful to kidney function, but the effect is slow; secondly, hormones are used to reduce cerebral edema, but long-term oral hormones have great side effects; thirdly, chemotherapeutic drugs are infused into jugular vein of brain surgery, but the effect is often not very satisfactory; fourthly, the effect is not very good. The fourth is cerebral fluid drainage in the thoracic or abdominal cavity of brain surgery, which directly drains the cerebral fluid into the thoracic and abdominal cavities, and sometimes the effect is still possible. In addition, intravenous bevacizumab has been reported to be effective, and we have also found that bevacizumab is effective in reducing cerebral edema. The main symptoms of cerebral edema are dizziness, headache, nausea and vomiting. There are chemotherapy and radiotherapy to treat brain tumor. Prednisone 30mg (6 tablets) once a day can be used as prophylactic medicine to reduce brain edema during head radiotherapy, and the dosage will be reduced when radiotherapy reaches 12-13 times, and half of the tablets will be reduced in 2-3 days. Chemotherapeutic drugs such as methotrexate, simustine, temozolomide, etc. can cross the blood-brain barrier. The drugs that pass the blood-brain barrier must have 2 conditions, one is fat-soluble and the other is small molecular weight. For the situation that it is difficult for drugs to pass the blood-brain barrier, some people have advocated radiotherapy first, and when the radiotherapy reaches a certain level, that is, 2000 cGy, the blood-brain barrier will be opened and the drugs can enter the head, but in fact, the effect of doing so is not particularly satisfactory. The best way to treat cerebral edema with Chinese medicine is to moxibustion Baihui point, the warmth of the Yang and water drugs (Li Zhaoshen) into a fine powder, honey into a paste, put on the hair removal Baihui point, and then moxibustion with moxa, the effect is very good; the second is the large vertebrae stabbing blood cupping, can significantly reduce cerebral edema, often blood out of the symptoms immediately relieved; the third is the head floating needle treatment, the treatment of dizziness and headache effect is also very good soon.