Is lymphedema considered reversible?

Sometimes. Acquired lymphedema during pregnancy or from overload of venous insufficiency may be treated successfully by wearing compression stockings during pregnancy and then treated by a vein specialist and a lymphedema specialist after the pregnancy. See a lymphedema specialist: lymphology association of north america and find a phlebolgy specialist: www.Phlebolgy.Org and www.Morrisonvein.Org for more.
No but treatable. Movement, exercise of the legs, and compression can help remove the fluid from the legs. If the skin and underlying tissue is not sclerotic I have found oral enzymes such as bromelain helpful in reducing lymphedema if used chronically.
Not curable. Unfortunately, lymphedema cannot be cured but it can be controlled. As drs. Westfried and morrison said, with exercise, compression, weight control, and lymphatic massage, the swelling can be well controlled much of the time, but it takes effort on your part to do that. If there is a venous disease component to the swelling (as there often is), vein treatment is beneficial.
Lymphedema. If it's a reaction to an acute event such as surgery maybe However if it suddenly develops without a cause more likely not reversible Treatment should include use of a compression stocking to aid in the development of alternative lymph channels.