M 21.For about 2mo. Constantly feeling tightness near heart. Had EKG and chest xray. Normal. Difficulty breathing sometimes. Stress from school or heart?

Probable stress. Probable stress at 21 y/o, but need to f/o cardiac. This is best done with advanced lipid biomarkers (including inflammatory markers and Insulin resistance evaluation) readiy available (and free) thru healthdiagnostic lab and singulex.