Jess,It's not an answer you are going to want to hear, but unfortunately you are going to have to get used to the fact that this is the new "you" at this point. This is just the way your body is. And it's why BFS or BCFS or anxiety or whatever you want to call it is so maddening at first. You will spend countless hours testing yourself, and countless hours looking for answers, and countless hours doubting and scoffing and looking for an "I told you so" exception, but unfortunately you're probably going to have a similar story to 99.99% of the people who have come through this board. Your body had a reaction to something that was toxic to it (stress, a virus, pollutants, medicine, whatever, it's really not important), and this is your body's natural reaction to dealing with that toxin. This is just the way your body is going to be for a while. It's the new you. You aren't sick, your body has been through a trauma, and now you are dealing with the aftereffects.I know you think that your case is unique and that you could be "the one", but trust me, you aren't. I have read countless case histories, I have seen the exact same symptoms pop up in hundreds of personal anecdotes on this board, and in five years and thousands and thousands of posts, there has never been one case where that person has ended up being what you think they have. They all turn up three or four years later, and they all say, "Hey guess what, I was fine. I just learned not to care about it after a while."Now obviously since you are still new at this, you will probably have a lot of mental adaptation stages to go through before you get there, but trust me, every single person on this board has had the exact same, or very similar symptoms, to yours, and guess what, everyone is still here. Unfortunately you are probably going to have to take some time to come to that exact same conclusion on your own (hey, it happens to the best of us), but you'll get there someday. You just have to learn that this is how you are going to be for a while.Through my experiences at the anxiety centre, I have learned that dealing with "bfs symptoms" is a 2 steps forward, one step backwards mental process. Every time you think you are getting better, you will have a mental relapse and panic over something that has worsened. But it hasn't worsened. It has just changed. BFS is all about randomness, weirdness, and change. In 3 months you will do a mental checklist of how your symptoms have progressed, and you will be stunned to find out that you can still do everything that you could do back at the start. It is all about perception, and how you think you are weaker and sicker than you actually are. That, to me, is the true damage caused by BFS. It's all about anxiety completely taking over your body, and leading your mind into places that are definitely not healthy. I have said it before, and I will say it again. Anxiety kills more people than MS or ALS combined. Once anxiety gets ahold of you, it's like a computer trojan horse virus. It worms its way in there, and it simply never lets up.So anyway, to answer your question in a much shorter manner: Yes, it is quite common for your body to rebel after doing anything strenuous. Go back and read any post you want from this website between 2004-2008. They all say the same thing. Yes, BFS sucks, but from a medical perspective you are still perfectly healthy. It might not be the answer that you want to hear, but this is just how you will be for a while.You can go looking for more answers than that if you want, but smarter and more experienced and more medically-inclined people than you and me have taken a crack at this, and they have driven themselves mad. In my opinion what we (or at least the vast majority of us) have around here is a normal-- albeit extreme-- body reaction to some sort of neurological toxin. It could have come from stress, it could have come from allergies, it could have come from a virus, it could have come from wherever. But as pretty much any doctor will tell you, it is nothing to worry about. It will eventually die down on its own, or in some rare cases, even go away entirely. But it will probably take a while.Being scared is normal. Being unreasonable is normal. We all go through it. But if there's one piece of advice I can give to you as a newbie, it is something I learned from the anxiety centre. It is three simple words. "Stop and Choose." Every time you feel yourself starting to freak out, stop for a second, take a deep breath, and ask yourself if you really want to continue down this panic attack. Do you REALLY want to be freaked out for the next 2-24 hours? Because remember, you have a choice. It might be very early in your BFS experience, but there are always ways to control your fears. You aren't sick. Eventually you will figure that out.Hope this helps,MarioA 5 month twitcher