Lymphedema is either primary or secondary. Primary cases are those that occur without any obvious cause. They may be present at birth (lymphedema congenita), occur later in life (lymphedema praecox), or develop after age 35, (lymphedema larda). Some cases are familiar as well as congenital. Primary lymphedema is more common in females and occurs more often in the lower extremities.
Secondary lymphedema is caused by injury, scarring or excision of the lymphatic vessels. In this country, this usually occurs as a result of previous radiation and/or surgery of the lymphatics. Such treatments are commonly given for cancers of the breast, uterus, bladder, ovary, and prostate or caused by trauma to or chronic infections of the lymphatic system.
It is estimated that there are over two million cases of secondary lymphedema in the United States, most the reult of breast cancer therapy. In third world countries, secondary lymphedema is much more common, owing to the prevalence of parasites which obstruct the lymphatics.