I’m 15, male and have been experiencing shortness of breath for some time now. Recently, I’ve also been experiencing chest tightness and muscle ache in my upper body(might be due to vigorous exercise during my Physical Education class). The shortness of breath is most apparent when I’m lying down flat or leaning while sitting. Should I be concerned? It’s 12.13 AM right now so I’m looking for a sign before I alert them.