Problem with Role of Lymphatic System
Problems with the lymphatic system can interfere with fluid balance in the body. Anything that interferes with the flow of lymph through a lymph vessel causes fluid accumulation in that part of the body drained by the vessel. Not only is fluid drainage impaired, inadequate protein removal alters the osmotic balance between the blood and the interstitial fluid so that even more fluid accumulates in the tissue. Such fluid accumulation is called oedema, and it often is visible externally as a swelling in that part of the body.
Figure: Swollen and obstructed lymph nodes cause elephantiasis
An extreme example of this is a condition caused in the disease filariasis by a parasitic larval nematode Wucheraria bancrofti in India. The larval forms are transmitted by mosquito to humans. They invade the lymph nodes and block lymphatic drainage so that portion of the body usually arm or leg and external genitalia become swollen, sometimes to the point of becoming grotesquely misshapen. This condition is known as elephantiasis.