When thrombophlebitis (inflammation of a vein that occurs when a blood clot forms) develops in varicose veins, this leads to venous stasis and eventually edema (swelling of soft tissues as a result of excess water accumulation) and ulcer formation.

Venous stasis refers to the congestion and slowing of circulation in veins due to blockage by either an obstruction or high pressure in the venous system, usually best seen in the feet and legs.

Edema is often more prominent in the lower legs and feet toward the end of the day as a result of the pooling of fluid from the upright position maintained during the day. Upon awakening from sleeping, patients can have swelling around the eyes referred to as "periorbital edema".