I have a friend who is experiencing alot of symptoms and i don't know what it is her symptoms are lightheadedness, persistent headache, tightness in chest, lack of focus, fatigue, nausea, intermittent fever, and dehydration she also told me she is underweight and the only thing i can think of is parasites I asked her about being outside the US but she said she was inside the US since July so i mean it can be a parasite in the US but i don't even know for a fact that it is a parasite I have seen monters insided me before on discovery health and it talks about parasites and some of her symptoms are from a parasite but may not be one I am just concerned she is about 17 I think, I am trying to help her as best I can. has anybody had a similar problem like this?