What is the Lymphatic System?



Lymphoedema is a swelling, which occurs in the body due to a failure of the lymphatic system. 

Most people will be aware that there are systems of veins and arteries throughout the body to carry blood to and from the heart.  There is also another system, which acts as a transport and drainage system. This is known as the lymphatic system. (Fig.1) 

The lymphatic system (green) works in harmony with the blood circulation system with its veins (blue) and arteries (red).

This system has several major functions, including playing a vital role in the body’s defence against infection.

Lymph is a colourless fluid, which forms in the tissues of the body.  It consists of proteins, water, fat, various cells, waste products and other foreign substances.  It normally drains back into the venous bloodstream through a network of lymph vessels and lymph nodes/glands.  As lymph travels through this network of vessels and nodes, dead or abnormal cells and other waste products are removed, and then the lymph is returned to the bloodstream.