The duration of coma in patients with brain hemorrhage is related to the site of bleeding and the amount of bleeding in the patient. If the patient has a small amount of bleeding, he or she may be awake in about 3 days. If it is a moderate amount of bleeding, the patient may be awake within 6 months. However, if it is a large brain hemorrhage and the patient is not awake within 3 months, the patient may remain in a coma and not awake. In the case of brainstem hemorrhage, even a small amount of brain hemorrhage may cause the patient to go into a coma. Because the superior reticular activating system is located in the brainstem, when brainstem hemorrhage damages the reticular structures and causes paralysis of the central nervous system, the patient may become comatose, and after aggressive and standardized cranial pressure-lowering treatment, the patient may improve in 3-5 days. In the case of massive brain hemorrhage located in the brainstem, the patient may be in coma for a longer period of time with more severe symptoms, and death may even occur; most of these patients are in a permanent vegetative state of survival and cannot be awakened. If the bleeding is located in the cerebral hemispheres and the amount of bleeding is small, some patients may not experience coma. If the coma is caused by massive cerebral hemorrhage from other sites, some patients with stable conditions can wake up after 1-2 weeks of standardized treatment by surgically removing the hematoma or applying dehydrating agents to lower the intracranial pressure.