By Riva Preil Background complete- you have made it through the anatomy, good job! Time to discuss the PATHOPHYSIOLOGY. Unfortunately, things donâ€™t always run as smoothly and perfectly as we just described, and dysfunction of the lymphatic system can result in LYMPHEDEMA. Lymphedema (LE) is swelling of the upper or lower extremities due to impairment in the lymphatic system. It can also develop in the trunk, head, neck, or genitals. It is a chronic disease and treatment involves lifetime management of the condition. There are two types of lymphedema, primary and secondary. Certain individuals are born with a congenital malformation of the lymphatic system, (ex. the vessels are too large or too small). This is known as PRIMARY LYMPHEDEMA. Furthermore, an initially healthy lymphatic system can develop problems through infection, obstruction, or damage. This is known as SECONDARY LYMPHEDEMA. Globally, the most common cause of lymphedema is filariasis, a parasitic disease that is caused by thread-like roundworms which occupy the lymphatic system, including the lymph nodes. The worms enter the lymphatic system through blood feeding mosquitos and black flies in certain tropical countries. In the United States, the most common cause of lymphedema is breast cancer-related surgeries that involve removal of affected axillary lymph nodes. Removal of lymph nodes results in impairment in the lymphatic system, and it disrupts the normal return of fluid to the venous angles. This can result in swelling of the involved upper extremity. Similarly, lower extremity lymphedema can develop after removal of pelvic and or inguinal lymph nodes (ex. due to prostate or gynecological cancer surgeries). Lymphedema can develop days, weeks, months, or even years after surgical node removal. Therefore, individuals who have undergone these types of surgeries should be aware of their predisposition towards developing the disease. Any abnormal swelling or changes should be reported to oneâ€™s physician immediately, because the prognosis is better if the disease is detected and treated earlier.