I'm 16...and a female. Recently my school has a had a case of some type of cold going around--really stuffy nose/runny nose, achy/itchy throat, cough, very slight fever for a day, and tiredness. I had this cold on top of allergies which required a visit to the doctor I was so miserable. He gave me Centri-D an off brand of an allergy medicine I forget the name of. It has sudafed in it so maybe this is why now I have been becoming extremely tired and lightheaded at school with very very very dull pain in the left rib cage. I feel like i need to close my eyes and sleep or I will pass out. I also get really hot like I'm having a hot flash. Could this be due to the medicine? (which by the way works great so far) Maybe I'm over tired? I have been extremely busy with school, soccer, the fall play, and school work. I eat regularly...i love food so I'm sure it;s nothing to do with my diet. Any ideas? Could I have a heart problem? I don't know what else it could be linked to that's why I posted here....Oh yeah I was recently diagnosed with exercise induced asthma. Please help!