My son doesnt drink often. in the last 7 months he has had 4-5 beers on 4 occassions and after each occassion he has gone into what seems like a long hangover. he doesnt get nausea. He sleeps literally around the clock for the first 3 days and the next four days he gets gradually better. He cannot remember most of what happens in that week. Does this mean he is allergic to alcohol or is just that it has some effect on his brain? Has anyone experienced anything similar?