Home > Can varicose veins cause a blood clot? > Can varicose veins cause a blood clot? Can varicose veins cause a blood clot? Home > Can varicose veins cause a blood clot? > Can varicose veins cause a blood clot? It’s very rare for varicose veins to cause blood clots, however it’s not impossible. The risk is very small, but can be increased by things such as flying, especially long haul. We would recommend wearing compression stockings on any flights to ease symptoms and keep the risk of deep vein thrombosis to a minimum.