Subarachnoid hemorrhage occurs when the patient has a sudden, severe headache with distending or bursting pain that is unbearable. The pain can be localized or full headache, and sometimes the pain can also appear in the upper part of the neck, persisting unrelieved or getting worse; mostly accompanied by nausea and vomiting; there can be unconsciousness or mental symptoms such as irritability, hallucinations, and talking nonsense; a few have seizures. Meningeal irritation signs (neck stiffness, headache, vomiting, etc.) may appear a few hours after the onset of the disease. In some patients, fundoscopic examination may reveal subvitreous hemorrhage, optic papillary edema, or retinal hemorrhage.
Patients usually have a sudden onset in the early stages, with headache occurring within seconds or minutes being the most common mode of onset. Patients can often clearly describe the time and circumstances of onset.
The onset is usually preceded by obvious triggers, such as strenuous exercise, emotional excitement, coughing, and alcohol consumption; in a few cases, the onset may occur under quiet conditions. About 1/3 of patients have headache, nausea, vomiting and other symptoms a few days or weeks before aneurysm rupture.
With the development of the disease, serious complications such as rebleeding, cerebral vasospasm, hydrocephalus, etc. may occur, manifested as aggravation or reappearance of the original symptoms, change of consciousness, focal neurological impairment (such as hemiparesis, aphasia, etc.), etc. The disability and mortality rates are high.