Sudden onset of severe headache may be cerebral hemorrhage or subarachnoid hemorrhage, which should be examined by cranial CT and cranial MRI to make a clear diagnosis. Both of these diseases are acute hemorrhagic cerebrovascular diseases, usually occurring suddenly during activity, and most patients have a history of hypertension. Common causes of cerebral hemorrhage and subarachnoid hemorrhage include cerebral aneurysms, arteriovenous malformations, and hypertension, which means that patients have a sudden increase in blood pressure on top of hypertension, leading to the rupture of an aneurysm or the rupture of a malformed blood vessel, which results in the onset of the disease, and generally has a higher fatality rate and disability rate. After the onset of the disease, the patient should be hospitalized in time for comprehensive treatment, surgical treatment when there are indications for surgery, and conservative treatment when there are no indications for surgery, including lowering the cranial pressure, cerebral protection, symptomatic and supportive treatment.