There is no evidence that varicose veins on their own cause deep vein thrombosis. It also appears that varicose veins do not significantly increase the risk of spontaneous thrombosis in women taking the contraceptive pill or hormone replacement therapy. There is however evidence that the presence of varicose veins leads to an increased risk of deep vein thrombosis at the time of major abdominal or pelvic surgery.
These reassurances are only applicable to patients with primary varicose veins - they do not apply to the very small minority of patients with varicose veins secondary to previous deep vein thrombosis.
Last reviewed 07/2019