I have a vein on the inside part of my arm thats causing pain and bruising.you can follow the vein and as youfollow it there is bruising?

Strange: actual bruising would mean there is a hole in the vein. Seems unlikely at 56 for you just to be bruising with no real pressure unless there is injury or a needlestick. Do you have very fragile skin and does this happen anywhere else in your body? Try not to irritate or "follow" this vein, and if you want, apply a warm compress. Have a doctor check if it doesn't go away.