Lymphedema is defined as a swelling of the arms or legs induced by an obstruction in lymph fluid circulation or by an abnormality in lymph fluid production. In most patients, lymphedema can be diagnosed from the clinical history and physical examination. The lymphangiogram and lymphangioscintigraphy are also used as additional diagnostic tools. Lymphedema developed from an obstruction of the lymphatic system is called secondary lymphedema. Lymphedema is classified into two categories: primary and secondary, and primary lymphedema is rare and is caused by a defect at birth or a congenital lymph system abnormality. The most frequent complication with lymphedema is cellulites. The protein-rich lymph fluid can be a source of bacteria proliferation leading to cellulites, which is an infection in the subcutaneous layers. But if therapy is started from the onset, the risk of infection in edema patients can be lessened. The primary management of lymphedema consist of conservative treatment called complex decongestive physical therapy: CDP or decongestive lymphatic therapy: DLT. The treatment includes skin care, manual lymph drainage, compression therapy, and exercise with bandage or compression garment. If the conservative management does not produce a sufficient effect or the edema worsens, surgical interventions such as microsurgical lymphaticovenular anastomosis and other techniques may be indicated. In Japan, the health insurance system does not offer enough support for patients with lymphedema. The treatment of lymphedema from the early stage is usually effective, and it is therefore necessary for clinicians to have a working knowledge of lymphedema management.