The lymphatic system has been much neglected in most Western scientific traditions. Contrasted with the heart, for example, the lymph is relatively unexplored. Perhaps, because lymph and lymph vessels are generally translucent they drew little attention in early anatomical study compared to organs, blood vessels, muscles and bones.

Hippocrates and Aristotle referred to "white blood" and "colorless fluid" but in the Middle Ages medical knowledge declined and the lymph was temporarily forgotten. In 1627 Asellius, in Milan, recovered the knowledge of the lymph.(38) The structure and action of the lymph system was still undefined by 1900(39) and the both the immunological function of the lymph and the actual lymphogenic process are not clearly understood even today.

In general, the lymphatic system is a network of organs, tissues,vessels, nodes and flow potentials. It collects interstitial fluid, infused with the by products of cellular activity, and transports it centrally where it rejoins the blood system. In this role it regulates endogenous metabolites and waste products.(40)

In addition, the lymphatic system is a primary component of the immune system helping to protect the body from a broad range of pathogenic factors.(40) It carries fluids infused with bacteria, virus, fungus into immuno-active lymph nodes where lymphocytes, reticular cells and macrophages kill or neutralize toxic or enemy cells, substances and organisms. In this role it regulates exogenous disease inducing agents.(40)

The lympatic system also has a nutritional function wherein it assists in bringing nutritional factors into proximity with the tissues. This was noted by Asselius in his original discovery of the chyle filled vessels of a recently fed dog.(38) In the 1970's the broad based nutritional (or trophic) function of the lymph system began to get deeper exploration.(41)

Like the early medical explorers in Europe, the founders of Oriental medicine also did not specifically note the lymph, except non-specifically as a component of the body fluids.(28,29) However, there is an important difference between the empirical science of Asia which did not clearly delineate the lymph and the deductive science of the West that gave the lymph little note.

In Western science, until recently the nearly invisible lymph, recieved little of the focus it deserves and few if any health generating strategies or modalities were based on its function. In the orient, where science is based on trial and error and the invisible "Qi" is honored, the results of healthy and unhealthy lymphatic function were noted in healthy individuals and contrasted in unhealthy individuals. Even though the lymphatic function itself was unknown and unnamed, its effects were generally ascribed to the proper action of Qi or Prana (energy) and fluids. In Asia an elaborate system for generating and circulating lymph was developed through the self care practices of Qigong and Yoga/Pranayama.