Subarachnoid hemorrhage (SAH) is a type of hemorrhagic cerebrovascular disease, and subarachnoid hemorrhage is one of the most common neurological emergencies, with an incidence of 6% to 10% of acute cerebrovascular disease. There are two types of hemorrhage: primary and secondary. Primary subarachnoid hemorrhage is caused by the rupture and bleeding of blood vessels on the surface and base of the brain, and the blood flows directly into the subarachnoid space. It is also called spontaneous subarachnoid hemorrhage. The main clinical features are rapid onset, severe headache, mostly tearing or severe distension, frequent vomiting, and positive meningeal irritation signs. Some patients have psychiatric symptoms such as agitation, delirium, hallucinations, or accompanied by convulsions and coma, etc. It usually does not cause limb paralysis. In the early stage of brain CT scan, a high-density shadow in the subarachnoid space or ventricles is seen; lumbar puncture examination shows uniform and consistent bloody cerebrospinal fluid with increased pressure. The most common causes of primary subarachnoid hemorrhage are congenital intracranial aneurysms and vascular malformations. Parenchymal or ventricular hemorrhage, traumatic subdural or epidural hemorrhage flowing into the subarachnoid space is secondary to SAH. The prognosis of subarachnoid hemorrhage is related to etiology, age, aneurysm site and size, bleeding volume, increased and fluctuating blood pressure, comorbidities, and timely surgical treatment. The prognosis is poor in cases of confusion or coma at onset, advanced age, high systolic blood pressure, large bleeding volume, and large aneurysms of the anterior cerebral artery or vertebrobasilar artery; half of the survivors are left with permanent brain damage and common cognitive impairment. Aneurysmal subarachnoid hemorrhage has a high mortality rate, with approximately 20% of patients dying before reaching the hospital, 25% dying after the first hemorrhage or from comorbidities, and approximately 20% dying from rebleeding without surgical treatment, with death occurring in the first few days after the hemorrhage. Ninety percent of patients with intracranial AVM rupture recover with a low risk of rebleeding. Surgical treatment can reduce or avoid the risk of rebleeding. Acute or subacute ventricular enlargement within hours to 7 days after subarachnoid hemorrhage, resulting in acute obstructive hydrocephalus . suggests a poor prognosis. If bilateral lateral ventricular dilatation and lumbar puncture pressure can be found early, suggesting acute obstructive hydrocephalus, immediate ventricular drainage should be performed, which can sometimes turn the situation around. Ventricular enlargement can occur weeks or years after subarachnoid hemorrhage, and normal cranial pressure hydrocephalus , a clinical syndrome due to multiple causes, is also known as occult hydrocephalus, low pressure hydrocephalus, traffic hydrocephalus, or hydrocephalic dementia. The three main signs of normal pressure hydrocephalus are mental disturbance, gait abnormalities, and urinary incontinence. Personality changes, epilepsy, extrapyramidal symptoms, strong grip reflex, and sucking reflex may also occur. Central paralysis of both lower extremities occurs in late stages. Ventriculoperitoneal shunt shunt is required. Signs of onset A small number of patients have headache, dizziness, vision changes, or neck stiffness within 2 weeks prior to onset, and these manifestations may be prodromal symptoms of subarachnoid hemorrhage. These manifestations may be precursors to subarachnoid hemorrhage. It is generally more common in young people than in the elderly, and is often clinically misdiagnosed as migraine or cervical spondylosis. The interval between the prodromal symptoms and the occurrence of hemorrhage is about 2-3 weeks. About half of the prodromal symptoms are caused by repeated small amount of blood leakage, and the extravasated blood can cause some fibrotic adhesion reaction around the vessel wall or aneurysm wall to play a hemostatic role. Treatment 1.Medical treatment SAH patients should be hospitalized for supervised treatment, absolute bed rest for 4-6 weeks, head of bed elevated 15°-20°, ward kept quiet, comfortable and dark light. Avoid triggers that cause increased blood pressure and cranial pressure, such as forceful defecation, coughing, sneezing and emotional excitement, to avoid re-rupture of aneurysm. Prevent arrhythmias with cardiac monitoring and pay attention to nutritional support to prevent complications. Avoid the use of drugs that damage platelet function such as aspirin; lower cranial pressure, prevent rebleeding, prophylactic application of calcium channel antagonists and cerebrospinal fluid release therapy. Surgical treatment is an effective method to eradicate the cause of the disease and prevent recurrence. (1) Aneurysm: The final surgical treatment of ruptured aneurysm is usually aneurysm neck clamping, aneurysm resection and so on. The patient’s state of consciousness is closely related to the prognosis, and the clinical use of Hunt and Hess grading method is useful for determining the timing of surgery and determining the prognosis. Surgery in patients who are fully awake (Hunt score I and II) or mildly unconscious (grade III) improves clinical outcome, while patients who are lethargic (grade IV) or comatose (grade V) do not seem to benefit. The optimal timing of surgery remains controversial. Current evidence supports early surgery (2 days after bleeding), which shortens the period of risk of rebleeding and allows treatment of vasospasm with volume expansion and pressure-raising agents. Treatment of unruptured aneurysms should be individualized, with younger patients with a family history of aneurysm rupture and low surgical risk appropriate for surgery and patients with asymptomatic aneurysms appropriate for conservative treatment. Endovascular interventions are used to treat aneurysms with super-selective catheter techniques, detachable balloon or platinum microspring coil embolization. (2) Arteriovenous malformation: Striving for total resection is the most reasonable, and blood supply artery ligation, endovascular interventional embolization or gamma knife treatment can also be used. Since the risk of early rebleeding of arteriovenous malformations is much lower than that of aneurysms, surgery can be performed at an elective stage. Post-treatment precautions After subarachnoid hemorrhage, active functional training is required. For medication, nerve-nourishing, energy-boosting, and blood-boosting drugs are sufficient. For example, sodium cytarabine, thromboxane, chandan, and so on. In general, there is no contraindication to the diet, just provide easily digestible and absorbable food. It is recommended to go to the rehabilitation department of acupuncture and moxibustion for a period of time. And actively perform functional training.