I am European with no asian blood only Irish/British, Sometimes i get the flush and sometimes i dont.  Most times i get it i am hungover/tired but sometimes if i am drinking with a hangover i wont get it and if i dont have a hangover i will get it. It started with certain drinks so avoided them drinks but now it is every drink. When i do get the symptoms i get it really bad, sometimes my whole body can go red and its always really patchy which makes it more obvious. How come sometimes its there sometimes it isnt? its very frustrating.