Gf is fatigued w/ sob (shes a runner & can barely walk the stairs w/out being winded), joint pain, bruising/petechiae on arms/legs, chest pain.what?

Important case: This sounds like an important case. A normally healthy person with these symptoms may have an abnormal blood and platelet count. Most doctors would at least obtain a screening blood count. She should see a doctor. This should be done soon, like in the next day.

See MD ASAP!: Your description suggests 2 sets of problems that very well could be related to a blood disorder. The fact that she's a runner and short of breath raises the possibility that she may have a very significant anemia and, in concert with the bruising , she also has something potentially affecting her platlets. She should call and see a physician ASAP!!!