Hi there, I am a 20 year old active female- 5 8, 105lbs and I have recently been having frequent heart palpitations- where I can see my heart beating through my skin, shortness of breath-to where I have to sit down because I can t walk more, tightness in my chest/upper back and increased sweating from little exertion. My resting heart rate is 120 and I am not sure why I am getting these palpitations, trouble breathing and tightness just from walking down the street. Any help/suggestions on what this could be?