Duplex scanning for reflux in the lower limb veins should be performed with the patient in the standing or upright position, with the assessed leg rotated outward and the heel on the ground, and with weight put on the leg not being evaluated.[3,9] A recent study found that, although there is no standardization on how to induce a retrograde flow of blood, the patient is usually asked to perform the Valsalva maneuver, which creates high pressure in the venous system and causes blood to back up, revealing the presence of any reflux.[9] With varicose veins and CVD, the venous duplex scan usually reveals venous reflux in the superficial veins in 90% of patients, with 70% to 80% being reflux occurring in the GSV.[3]