I have thrown up four times this year since January (it is now November). The first time I threw up, I thought I had food poisoning, as I was throwing up from 10PM to about 7AM the next morning and felt sick the rest of the next day. The second time I threw up for five hours starting at about 4AM. These events happened probably about two months apart. I would go to bed and wake up feeling very sick, and lie there for about half an hour before I threw up. Last month I started feeling sick as I was going to bed, tried to sleep it off and threw up once then was fine. Today I woke up at 6AM feeling very sick and threw up at 6:30AM and still feel sick. I'm starting to wonder if it is due to my sleep pattern, I don't remember before but lately I've been getting 5-6 hours a night.

I know it seems like it doesn't happen that often, but I've never had this happen so many times throughout a year with no apparent reason. Do you guys have any idea what it is? Should I visit a doctor? Thanks for your help.