I have been to the hospital 5 months ago as I took an overdose and I had a drip in my arm for about 26 hours for my antidote.. From then I have had a small hard lump in my vein in my arm and it has spread since January, there is now 3 Hard bumps runinng up the inside of my vein.. they sometimes make my arm tingle and very numb but there is no redness at all or anythink visible to the eye and it is painless but they are causeing disscomfort. What could it be as I am getting very worried. Charlotte x