My best friend called me. She woke up in the middle of the night last night with a feeling of "heaviness" in her chest & felt like she couldn't get a full breath. She's 31 yrs old, in overall good health...but she is a smoker & is on birth control. There is also a strong family history of cancer (her mother's had Leukemia twice, is currently in treatment). I told her to go to urgent care. She did, she has elevated counts and they sent her to emergency. She's on her way now, I'm very concerned! What could be the possibilities here?