Arachnoid hemorrhage, or subarachnoid hemorrhage, is usually treated and may recover in about 4-6 weeks, but it cannot be generalized. Subarachnoid hemorrhage is a very serious cranio-cerebral disease, mainly due to the rupture of diseased blood vessels at the base of the brain or on the surface of the brain and the direct flow of blood into the subarachnoid space, resulting in a variety of clinical syndromes, commonly associated with intracranial aneurysms, cerebrovascular malformations, anomalous vascular network disease at the base of the brain, and entrapment aneurysms. After timely and effective treatment, the milder cases can gradually improve in about 2 weeks at the earliest and may recover in about 4-6 weeks. Second, the prognosis is worse in older and frail patients than in younger patients, and the prognosis for aneurysmal subarachnoid hemorrhage is worse than for non-aneurysmal subarachnoid hemorrhage. During the rehabilitation period, it is necessary to actively control the risk factors, quit smoking and alcohol, avoid emotional excitement; keep the bowels open to prevent constipation; and actively treat the primary disease, such as aneurysm.