Is subarachnoid hemorrhage (SAH) a separate disease? A subarachnoid hemorrhage is a rupture of a blood vessel at the base of the brain or superficial part of the brain, and blood enters the subarachnoid space directly. It is not a stand-alone disease, but a combination of many causes. Intracranial aneurysms are the most common cause, with about 65-85% of cases reported to be due to ruptured intracranial aneurysm bleeding. What are the manifestations of SAH? The typical clinical manifestation of SAH is a sudden onset of severe headache, often described by patients as “the worst headache of my life”, accompanied by a history of photophobia, vomiting, and impaired consciousness. Rupture of intracranial aneurysm can cause a series of pathological changes such as SAH, intracerebral hematoma, cerebral vasospasm, cerebral ischemia, cerebral edema and hydrocephalus, with high mortality and disability rates. According to statistics, patients who survive the first conservative treatment have a mortality rate of more than 80% for rebleeding. Since the natural course of this disease is extremely dangerous and the complications are extremely serious, such patients should be transferred to a neurosurgery department with treatment conditions for diagnosis and treatment as soon as possible. How is SAH further diagnosed? Patients with SAH should undergo a whole brain angiogram (DSA, CTA or MRA) to determine the presence, number, size, location, and shape of the aneurysm. Among them, DSA is the gold standard for diagnosing intracranial aneurysm. If an intracranial aneurysm is not detected on the first imaging, DSA will be repeated in the future. How to treat SAH patients? Patients with SAH who have not yet been diagnosed should be closely observed and rest in bed. The patient should be sedated, analgesic, anti-emetic, laxative, avoiding coughing and mental stimulation, etc. The patient should also be treated with medication to prevent cerebral vasospasm, cerebral ischemia, seizure prevention and control of high blood pressure. How to treat intracranial aneurysm patients? Because intracranial aneurysms carry a risk of rebleeding and have a high rate of death and disability due to aneurysm rupture and re-rupture, they should be treated etiologically. Traditional surgical treatment involves craniotomy to clamp the aneurysm neck and exclude the aneurysm from the cerebral circulation. The optimal timing of surgery depends on the clinical status of the patient and other relevant factors. Patients in good clinical condition and those with combined hematoma causing occupying effect or manifestations of rebleeding should be operated early (i.e., within 48-96 hours after SAH). Early surgery is difficult due to brain swelling, and the incidence of disability increases, while the incidence of rebleeding decreases. Surgery should be delayed in patients with poor clinical status (i.e., 10-14 days after SAH). For patients with too poor clinical status, equivalent to Hunt-Hess grade 4-5, surgery is generally withheld. The operative mortality and disability rates are closely related to the patient’s condition, aneurysm size, location, and degree of cerebral vasospasm. Advances in endovascular treatment techniques offer new treatment options, even in the acute phase. Remember: physicians and families should be on high alert for patients with SAH! Never take it lightly! Taking proactive measures to find and treat the cause of the bleeding is the key to treatment!