Veins in arm surfacing and painful

I am a 50 y.o. woman, i am anemic, i recently was hospitalized and had several I.V. sites in my arms, when i got out of the hospital, i went for a checkup and had some blood drawn, that night i started having pain in my arms and my veins were surfacing and getting very big and it was so painful. it felt like my veins would bust!  A few days went by and it happened numerous times and when i raise my arms it goes away, last night however it started happening in my legs.  Is this phlebitis, varicose veins, i am not in good health and i only weigh 77.2 lbs and cannot seem to gain and keep weight on.  I also have had hodgekins in 79 and beat that then in 81 i had cervial cancer, and then in 99 i had anal cancer, from all the chemo and radiation treatments i had to have a chest tube and part of my left lung removed, my left side and breast hurts constantly. I am afraid that this thing happening in my veins may be life threatening.  Is this something i should worry about????  Thank you