I Am A 28 Yr Old Female And I Have

I am a 28 yr old female and I have often exercised, but not for some time now. IAm now overweight and have started going to the gym again, and whenever I do any arm weight machines my two neck veins feel very tight, almost like it's too small to get the blood pumping through. My pulse is hammering and feels like it will burst out of my neck. After about 20 seconds after I stop the exercise it goes away. What is this and how can I stop it from happening?