Subarachnoid hemorrhage refers to a clinical syndrome caused by the rupture of a diseased blood vessel at the base or surface of the brain and the direct flow of blood into the subarachnoid space, also known as primary subarachnoid hemorrhage, which accounts for about 10% of acute stroke and is a very serious and common disease. The incidence rate in China is about 2.0/100,000 people per year according to the World Health Organization survey, and 6-20/100,000 people per year have also been reported. It can also be seen as secondary subarachnoid hemorrhage due to intracerebral parenchymal, ventricular hemorrhage, rupture of epidural or subdural vessels and blood penetrating the brain tissue into the subarachnoid space. The most common cause of spontaneous subarachnoid hemorrhage is rupture of intracranial aneurysm, followed by bleeding due to arteriovenous malformation; the onset may be preceded by triggering factors such as forceful defecation, coughing, violent mood swings, lifting heavy objects, strenuous exercise, and sexual intercourse, with variable onset, followed by severe headache, often described by the patient as the worst headache ever, feeling like the head is going to explode, often accompanied by nausea, or even vomiting. even vomiting, and in severe cases there can be impaired consciousness, manifested as drowsiness, but can be woken up, or coma, and even deep coma when the bleeding is large. Once the onset of the disease, go to the hospital as soon as possible, try to avoid shaking during transportation, cranial CT as soon as possible, and once diagnosed, do further vascular examination (cerebrovascular MRA or DSA) to find the cause of bleeding, and then treat the cause. Emergency treatment 1.Sudden severe headache and vomiting should be suspected of subarachnoid hemorrhage, and should be sent to the hospital promptly; 2.Let the patient keep the head in a high lateral position as much as possible to avoid obstruction of ventilation by the back of the tongue, and clean the vomit in the mouth in time to avoid inadvertent aspiration into the airway; 3.Avoid long-distance transfer as much as possible, and choose the nearest medical unit with conditions for treatment; 4.The patient should be escorted by medical personnel and observed at all times when being transferred 5.Treatment such as dehydration and hypotension should be given before transfer, sedative and painkiller should be given, and absolute bed rest should be given; 6.Avoid vibration as much as possible during transportation; 7.Ventricular puncture and drainage or lumbar puncture to release hemorrhagic cerebrospinal fluid is feasible in case of large amount of bleeding; cranial CT or lumbar puncture can confirm; 8.Actively find out the cause, and for intracranial artery and intracranial vein malformation, confirm the cause and perform surgery to eradicate it afterwards; 9.Patients should be transported to the hospital. 9. Pay attention to the change of blood pressure at any time; 10. Keep the patient in a happy mood and avoid emotional tension.