About two months ago I started lifting weights and exercising to get back into shape. I am 5'3" and 250lbs. I am not flabby, just heavy. I noticed after a month that my left shoulder was hurting. Now the muscles in my left arm are aching and tingling pretty much all the time. I don't have any other symptoms (shortness of breath, chest pain, dizziness etc.) My wife started massaging my shoulder and found a big knot that is very painful. I am trying to figure out if I need to see a doctor for the the left arm pain or is it caused by the knot. I also noticed that very rarely I have been sitting on couch and my upper body starts tingling and my heart rate jumps from about 75 to 126 for 5-10 sec then goes back to normal quickly. Sorry for the long post, any advice would be appreciated.