My Daughter Is 21 And Has Had Migraines For The

My daughter is 21 and has had migraines for the last several days, and she just called me from work saying she blacked out at work but didn't fall over. She also had heart palpitations yesterday at work as well. She is panicking and wants to go to the ER when she gets home. What do you think is going on with her? Should we go to the ER or just make a dr. appt? Thank you!