I was invited by my flat mate to try some cider (5% alcohol) upon hearing that I never drink. After half a bottle, my heart rate inceeases, and face, shoulders, and thighs turn red with an intense burning sensation. The same thing happened quite a while ago in Japan when I mistook what apparently is gin for lemon soda. And everytime this happens, I'll start to get sleepy, followed by waking up feeling a bit tired but better than how it started. Is it possible that my body cannot metabolize alcohol? Should I be worried about this?