For most surgeries, pillows are allowed after surgery. If the doctor does not allow you to have a pillow, it is due to the following reasons: 1. Lumbar anesthesia: also called subarachnoid anesthesia. A high head position can cause cerebrospinal fluid leakage/outflow into the epidural space, causing low cranial pressure headache. Therefore, after lumbar anesthesia, the patient should be de-pillowed and lie flat for 6 hours. 2, Confused patients, after surgery to go to the pillow lying down. Prevent the patient’s tongue root suffix to block the airway, causing asphyxia hypoxia. 3, after surgery, low blood pressure patients should go to the pillow lying down, to maintain intracranial perfusion pressure, to prevent cerebral ischemia. 4, cervical spine surgery, the cervical spine should be straightened after surgery to prevent cervical flexion and hyperextension.