Over last couple months I ve been experiencing fatigue , shortness of breath, turned blue after a five mile road race, dizziness and yesterday almost fainted after two of three mile run. When that happened I got very dizzy, stopped running and felt pins and needles over entire body. I walked last mile home, not easy. This morning woke very dizzy, exhausted, and short of breath, after 9+ hours sleep. Feeling slightly better but scared. Heart problem?? I m 42, female, athletic. Extreme stresss currently due to work.