Many people experience insignificant stinging or cramping if the needle goes to the vein. Inform your healthcare Experienced if it hurts lots. Pain could possibly consequence from the solution leaking within the vein to the tissue close to it. Normally, Mayo Clinic isn't going to demand a health practitioner referral. https://www.sgvascularctr.com/varicose-vein-treatment-in-singapore-from-the-perspective-of-a-vascular-surgeon/