My friend is having trouble getting a diagnosis because of the city she lives in, and she is currently in the hospital.
Her symptoms: High fever, dizzy, racing heart, coughing, severe headaches, constant throbbing "all over", increased need for sleep, and feels as though she will pass out at any given moment.
Can someone figure out the illness?
I can't really describe much of anything else because she lives awhile away from me, and this is all she has mentioned, but hopefully it'll start somewhere!
The dizziness and fatigue, accompanied by a racing heart are all symptoms of a cardiac ailment, such as an arrhythmia. She has probably had an EKG, and if that was normal, she may need further cardiac testing, such as an Echocardiogram or stress test. The coughing and fever point to a bacterial or viral infection, possibly originating in the lungs. I assume that she has probably had a chest x-ray since she is in the hospital. The doctors are probably trying to narrow it down from a list of infections with blood tests.
Surely the hospital will do blood work to check for lots of things. these symptoms could be from any number of health problems but they need to check her for the following (although the high temp is a sure sign of an infection somewhere)
1) H1N1 (or general flu)
2) Lyme disease (was or has she been outdoors a lot?)
3) Diabetes
4) Thyroid
Or any other numerous conditions that could have these symptoms but, like I said, the high temp is a sign of some type of infection!
sounds exactly like me, however i have a few more symptoms, but it sounds like anxiety, it's really horrible 
i get the high fever, dizziness racing heart, headaches, throbbin. the feeling of passing out, ect.
go on web mb .com.
The flu maybe?
go to an online med. website and look up these symptons