About a month ago I was experiencing some random pins and needles/ tingling sensation in different parts of my chest. Nothing painful and wasn't constant, but enough so that I was aware was unusual. Now I have in the past couple of weeks developed a heavy kind of tightness in my upper centre of my chest. It's not particularly painful but is uncomfortable and woke me up from my sleep this morning. Any ideas what it could be ? I haven't had this every day, but today was enough to get me concerned.I took two painkillers and it took away the discomfort but I can still feel its there.