A family friend had an aneurysm/hemorrhage in the middle of the night. Husband herd her fall on the floor, had to be flown for emergency surgery. She recovered, needed some therapy but is doing alright from what I heard.
CT without contrast for hemorrhage (noticable white spot), MRA for aneurysm, location and size predicts the outcome. Unless there is symptoms,family history or cases like renal tumour it's not often feasible to be scanned
My Stepmom had two colleagues dying on the spot due to an aneurysm last year. They felt weak or dizzy and within minutes were dead, pretty scary. Both around ages 40-50 only.
Unfortunately, everybody else in the hospital ward was suffering from a severe case of Werneke's aphasia and Korsakoff syndrome.