Hi , for a few years now I constantly now and then have a weird tightning sensation which seems to be feeling like its on my heart as if someone was squeezing and tighning it , It does feel like it's more to the left side of my chest and I understand the heart is directly in the middle of your chest , but I can honestly say it feels as if it is the heart , I am getting worried as it seems to be getting worse , I try to go to my gp but all I ever get told is it cannot be my heart etc ..... What do you think this sensation could be ?