Hi, I am a very active teenager. However, on occasion, following eating I have severe symptoms when I exercise. Normally I am fine. After eating and going out to exercise I first feel flushed, break out in a clammy sweat, get a headache and then it goes quickly into tightness in the chest, severe shortness of breath (as though I cannot breathe at all) and my face turns blood red. I panic and must sit down quick, I get very weak. It seems to only happen when I have eaten and exercise and it does not take a lot of exercise for the symptoms to occur. Any advice??