Overview: What is Lymphedema
The information in this section has been gathered from existing peer-reviewed and other literature and has been reviewed by expert dermatologists on the CSPA Medical Advisory Board.
The lymphatic system is a component of the vascular system and is a vital part of the immune system. It is comprised of a large network of low-pressure lymphatic vessels that help to carry a clear fluid known as lymph unidirectionally toward the heart. The human circulatory system reabsorbs approximately 17 litres of the on average 20 litres it processes through capillary filtration each day, with the remaining 3 litres of this interstitial fluid gets picked up by the lymphatic system. The lymphatic system is able to bring back this fluid back from the extremities and the gastrointestinal system to the heart with the aid of the contraction of skeletal muscle contraction on the lymph vessels and the unidirectional valves that prevent the reflux of lymph fluid backwards.
Lymphedema is the abnormal accumulation of lymph fluid outside normal body tissue (extravascular tissue) as a result of the lymphatic load surpassing the transport capacity of the lymphatic system
It can be classified as either primary or secondary lymphedema depending on the cause of the presentation.
- Primary lymphedema: lymphedema that occurs without a secondary factor and is generally due to a congenital condition of irregular development of the lymphatic vessels. Primary lymphedema is further classified according to the age of presentation.
- Congenital lymphedema is present at birth or within the first two years of life.
- Lymphedema praecox commonly presents around the type of puberty.
- Lymphedema tarda is usually seen after the age of 35 years.
- Secondary lymphedema is lymphedema that occurs due to other conditions or treatment regimens. Causes of secondary lymphedema include:
- Inflammatory disorders such as arthritis, sarcoidosis
- Lymph node dissection, such as for melanoma or breast cancer
- Cancerous obstructions such as lymphoma, Kaposi’s sarcoma, retroperitoneal sarcoma
- Cancer treatment
- Surgical excisions, such as a mastectomy or prostatectomy
- Parasitic infections
- Primary lymphedema typically affects the lower limbs and is seen in higher proportions in females.
- Two-thirds of all cases of lymphedema are unilateral.
- Lymphedema affects approximately 200 million people worldwide.