Many people sense insignificant stinging or cramping in the event the needle goes into the vein. Tell your healthcare Skilled if it hurts lots. Suffering could outcome from the solution leaking within the vein in to the tissue close to it. As per this journal post "Chronic venous insufficiency (CVI) https://www.sgvascularctr.com/what-surgery-is-available-for-varicose-veins/