Lymphedema
Also known as: lymphoedema
Lymphedema is chronic swelling caused by impaired lymphatic drainage, which allows protein-rich fluid to accumulate in the interstitial tissues. It most often affects an arm or leg and, over time, produces firm, non-pitting swelling with skin thickening.
The lymphatic system returns interstitial fluid and protein to the venous circulation. When lymphatic vessels or nodes are absent, obstructed, or destroyed, that fluid stays in the tissue. Because the retained fluid is protein-rich, it draws additional water osmotically and triggers chronic inflammation, which over time replaces soft edema with fibrous and fatty tissue.
Lymphedema is classified as primary or secondary. Primary lymphedema results from congenital or hereditary malformation of lymphatic vessels and is grouped by age of onset — congenital, praecox (adolescence), and tarda (after about age 35). Secondary lymphedema is far more common and follows damage to a previously normal system: lymph node dissection or radiation for cancer, tumor obstruction, recurrent infection, trauma, severe obesity, or, globally, filariasis from parasitic infection.
Clinically, swelling usually begins distally and is unilateral. Early edema may pit, but established lymphedema becomes non-pitting, with skin thickening, hyperkeratosis, and a peau d'orange texture. A positive Stemmer sign — inability to tent the skin at the base of the second toe or finger — supports the diagnosis. Distinguishing features matter: chronic venous insufficiency produces pitting edema with hemosiderin staining and ulceration near the medial malleolus, while lipedema is bilateral, symmetric, spares the feet, and is tender. Recurrent cellulitis and lymphangitis are the main complications, and lymphangiosarcoma is a rare late one.
Management centers on complete decongestive therapy — manual lymph drainage, multilayer compression bandaging followed by compression garments, remedial exercise, and meticulous skin care. Both the NPTE for physical therapists and the NPTE for physical therapist assistants cover lymphedema in the other systems content area, and the CCMA exam addresses it among diseases and disorders of the lymphatic system.
Key takeaways
- Lymphedema is protein-rich interstitial swelling caused by impaired lymphatic transport.
- Secondary lymphedema, from node dissection, radiation, tumor, infection, or trauma, is much more common than primary lymphedema.
- Swelling typically starts distally and is unilateral, becoming non-pitting with skin fibrosis as it progresses.
- A positive Stemmer sign helps distinguish lymphedema from venous edema and lipedema.
- Complete decongestive therapy — manual lymph drainage, compression, exercise, and skin care — is the standard approach, and recurrent cellulitis is the main complication.