I have had daily chronic headaches and migraines since I was 15 years old (I'm 37 now). I have tried all kids of meds. Now I am taking Corgard as a preventative. I woke up yesterday morning with a terrible headache. I took Excedrin and it helped, but I suffered all day with it. I went to bed at about 10:30 with a headache. I woke up at about 12:30 and it was gone. Thenk I woke up at about 3:00 and there it was again and woke up about 6:00 and it was gone. Then I got up at about 8:30 this morning and there it was. It has been hurting so bad this morning that I took a Relpax (for Migraines) It hasn't kicked in yet. Why does the headache come and go like that?