Pupil dilation in cerebral hemorrhage implies a poor prognosis. Normally, both pupils are equal in size, 3-5 mm in diameter, >5 mm is called dilated pupil, and <2 mm is called reduced pupil. If a patient has dilated pupils on one or both sides, coupled with the fact that the patient is unconscious and cannot wake up after a brain hemorrhage, brain herniation may occur, which is a sign of a poor prognosis for brain hemorrhage. Therefore, the prognosis is not good if the pupils are not equally large or dilated bilaterally. If one pupil is dilated, i.e., one pupil is more than 5 mm, and both pupils are unequal, the hippocampal sulcus is herniated. If both pupils are >5 mm, this indicates a herniation of the greater occipital foramen. Brain herniation is a very serious comorbidity due to increased intracranial pressure, where brain tissue runs from a place of high pressure through a gap to a place of low pressure, suggesting a poor prognosis.