Lymphedema Causes and Risk Factors

Primary Lymphedema

Primary lymphedema stems from congenital lymphatic system abnormalities that impair lymphatic transport capacity from birth or develop later in life due to inherent defects in lymphatic vessels or lymph nodes 1, 2

The American College of Surgeons recommends that surgical lymph node dissection, particularly axillary lymph node dissection for breast cancer, is a leading cause of secondary lymphedema, with a risk of 30-50% in patients 1, 2
Pelvic surgery with lymph node dissection is the most common cause of unilateral lower extremity lymphedema 3
The extent of lymph node removal matters, with removing five or more lymph nodes substantially increasing lymphedema risk 1, 2
Radiation therapy, particularly to supraclavicular lymph nodes or axilla, significantly elevates lymphedema risk, especially when combined with surgery 2, 4
Pelvic radiation damages lymphatic channels and increases lower extremity lymphedema risk 3
Combined surgery and radiation therapy creates additive risk beyond either treatment alone 2
Malignancy causing lymphatic obstruction through direct tumor compression or invasion of lymphatic vessels can cause secondary lymphedema 3
Recurrent infections, particularly cellulitis, in affected areas damage lymphatic vessels and increase lymphedema risk 2
Chronic venous insufficiency can contribute to lower extremity lymphedema development 3

Obesity, with a BMI >30 kg/m², is a critical modifiable risk factor that exacerbates lymphedema severity and correlates with higher International Society of Lymphology stages 3
The National Comprehensive Cancer Network recommends that weight loss should be mandated for overweight/obese patients to prevent or reduce lymphedema risk 3, 4, 5

Lymphedema may occur immediately after treatment or develop years later, up to 11-30 years post-treatment, making lifelong surveillance necessary 4