How long does it take swelling from dvt to go down?

It can take a while.: Firstly it might depend on how swollen you started out. Secondly it matters if you had active treatment (catheter based) or passive (drugs only). With non-active treatment it can be a while for your body to break down enough of the clot to allow blood to flow again. Until that time there is blood backing up and taking non-standard routes back to the heart resulting in swelling.

Varies: Dvt results in a clot in a deep vein. The larger vein, usually the longer it takes for the swelling to resolve, and sometime, the swelling will be permanent. Large veins such as the iliac or femoral tend to have more swelling than smaller veins such as the popliteal or tibial.

It depends: Early treatment with blood thinners is important to prevent a life-threatening pulmonary embolism, but does not treat the existing clot. Early in treatment, blood thinners are given to keep the clot from growing or breaking off and traveling to the lung and causing a life-threatening pulmonary embolism. Over time, the body will dissolve the clot, but the vein may become damaged in the meantime.