A 52-year-old woman presents to the emergency department with a sudden onset of severe headache. She describes it as “the worst headache of my life,” which began abruptly while she was reading at home. The headache is diffuse but more intense at the back of her head. She also reports nausea, vomiting, and photophobia. There is a past medical history hypertension, diagnosed 5 years ago, poorly controlled due to inconsistent medication adherence. She is also a smoker with a 20-pack-year history.