Special drowsiness after surgery may be a normal reaction to anesthesia, but it can not be ruled out that it is caused by brain diseases, electrolyte disorders, the patient’s state should be closely observed, and if necessary, the doctor to deal with. 1. Normal reaction to anesthesia: analgesic, sedative drugs and other anesthetics may be used during surgery. After awakening, drowsiness may also occur. Generally, after the anesthesia drugs are completely metabolized, the mental state can return to normal. 2. Brain diseases: some patients with cranial brain surgery can affect the nerves, resulting in patients with impaired consciousness, so there will be drowsiness after the operation. In addition, cerebral infarction, cerebral hemorrhage and other brain diseases can affect the brain function and thus drowsiness, at this time, we also need to closely observe the patient’s limb activity and other related states. 3. Electrolyte disorders: The trauma of surgery is relatively large, and excessive bleeding during the operation leads to low blood volume or electrolyte imbalance, resulting in electrolyte disorders, such as low potassium, low sodium, etc., which may also lead to drowsiness, accompanied by nausea, vomiting, dizziness, etc., and in severe cases, coma and sudden death may even occur. If the patient has persistent drowsiness after surgery, it should be taken seriously, and if necessary, be examined by a doctor and be treated accordingly.