What is the Lymphatic System?

To better understand lymphedema, we first must understand the normal lymphatic system (see diagram). This system functions parallel to the circulatory system and consists of lymph vessels, lymph nodes, and lymphoid tissues. The most important role of the lymphatic system is to absorb and transport large molecules (including protein and cellular debris) which are too large to be collected by veins and venous capillaries. This lymph fluid is then transported to lymph nodes that act as “filtering stations” in the body. In the lymph nodes, cells from the body’s natural defense system, called lymphocytes, help fight bacteria and viruses. 

Networks of the lymphatic system are situated in several areas of the body with a specific drainage pathway for each individual area. 

Superficial Lymph Nodes Include:

  • Axillary: Located under each arm, these nodes receive fluid from the arm, chest, back, and breast tissue.
  • Inguinal: Located at the bend of the hip, these nodes receive fluid from the leg, lower abdomen, gluteal region, and external genitals.

Deep Lymph Nodes Include:

  • Supraclavicular: Located at the neck just above the collar bones, this important node group receives fluid from the head and shoulders. If indicated, the treatment of these lymph nodes precedes all other treatment. 
  • Deep Abdominal/Pelvic Nodes: The abdomen is richly invested in lymph nodes—they surround the organs and intestines. These nodes also receive fluid from the superficial inguinal area as well. Congestion in this area alone can cause swelling in the lower extremities, abdomen, and genitalia.

Lymphatic tissue is found in other areas of the body including the tonsils, spleen, intestinal wall, and bone marrow. 

Diagram of the lymphatic system