Subdural effusion precautions mainly include: 1. If the amount of subdural effusion is relatively small and does not cause midline shift, the most important thing in the treatment process is just dynamic review. If symptoms of neurological impairment occur, such as weakness, dizziness, headache, vomiting and other symptoms in one limb, it is necessary to go to the hospital to review the head CT to assess whether the subdural fluid has progressed. 2. If the amount of subdural fluid is relatively large and causes midline shift, surgical treatment is required. Patients who have undergone surgical treatment also need dynamic review of head CT and anti-infection treatment to assess the effect of surgical treatment. Antibiotics must be administered to prevent intracranial infection before removal of the head drainage tube.