For years now I've had an awful gag reflex, I'm 19 years old living in London, UK. Sometimes if I'm very tired I gag, even to the point I throw up. If I'm brushing my tongue that also makes me gag, thinking about gross things, smelling gross things and even looking at them! Also, my weak stomach. I can eat the same food as other people, but I'm the only one who will get ill from it, it's happened quite a few times with takeaways such as pizza with meat on, chinese food etc. In the morning I usually feel too nauseous to attempt to eat breakfast.

When I was in the dentist gettting an x-ray the thing you put in your mouth kept making me gag, even breathing only through my nose it didn't help. I don't remember having this problem as a child, it's only from the age of 13 onwards, however, my stomach has always been pretty weak.

Have you ever talked to your doctor about this? If so, what tests did he/she run? Have they ever tested if you have a low tolerance to glutton? Acid reflux? Esophageal hernia?

Your first step is to talk to your doctor about this. There's really no way for anyone online to offer you a diagnosis, or treatment.

Millions of years ago when we were still in Africa we would live in a tribe and probably all eat the same thing. If we were feasting upon something and someone got sick then it was an indication that what they were eating was off. So most would purge to prevent getting sick themselves. It is where the sympathy vomiting comes from. It is also isn't unusual to have a gag reflex like yours. It is inconvenient at times, but not unusual.

With your stomach, you could have a sensitivity or allergy that you don't know about. I would go to the doctor and get an allergy test, or a referral to a allgerist.

Good Luck.