Thyroid disease is not known to cause spider veins, reticular veins, varicose veins or venous insufficiency and a PubMed search done on 1-7-2017 does not show any results. However, this does not mean that inflammatory processes in the body, like thyroiditis, does not accelerate inflammatory venous disease. I would wear compression stockings and I recommend microfiber graduated 20-30 mm Hg knee high or thigh high stockings from VenaSmart. Hratch L Karamanoukian MD FACS certified vein specialist (ABVLM)
There is no obvious relationship between thyroid disease and spider veins. Spider veins develop due to reflux in adjacent superficial veins.