Gloria is a 24-year-old female who visits the student health center complaining of unilateral headaches that she describes as throbbing. Gloria experiences these headaches 5-10 times per month, and an episode can last up to 24 hours. During the headache, she is sensitive to light. She feels better lying down alone in a dark room. She has tried acetaminophen with little effect. The Nurse recognizes that her headache is most likely which type?