Hi
Welcome to the MedHelp forum!
First of all I appreciate your effort to go off the drugs and succeeding in it. In many people it is difficult to find veins as they are embedded more deeper than in others.
Since you had been using your veins a lot, there is a chance that there is thrombophlebitis or infection of the veins or there are clots or thrombus in the veins. Also if the doctors and nurses have pricked you in trying to locate a vein, it can cause pain. If the pain and soreness has started after the doctors and nurses pricked you, take an anti-inflammatory and get a warm oil massage done on your arms. If the soreness and pain has been for long, you will need a proper checkup.
Hope this helps. Please let me know if there is any thing else and do keep me posted. Take care!
Hmm, Im no doctor but it could because your veins collapsed.