Hi and welcome to Healthcare Magic. Thanks for your question...
You may have developed a thrombo-phlebitis
(i.e. an inflamation of the vein with blood clots
) which is the reason for the hardened chord-like feel over the vein.
Please remember, that iv drug abuse
can cause many harmful and dangerous consequences. Blood clots and infections can be transmitted through the blood stream to the heart and can cause life-threatening consequences also. If you are finding it difficult to give up drugs, please seek the help of a professional.
Wish you all the best.
- Dr. Jonas Sundarakumar