The lymphatic system forms part of the immune system, helping to deal with infection at a local level. It also cleanses body tissues and helps to maintain a balance of fluids in the body. It can be likened to a waste disposal system, taking tissue fluid, bacteria, proteins and waste products away from the tissues around skin, fat, muscle and bone.

Once inside the lymphatic vessels (which initially are barely visible just under the surface of the skin) the tissue fluid becomes known as 'lymph' and it is then transported in one direction by increasingly larger and deeper lymphatic vessels.

At some point in its journey, lymph will pass through a lymph node, or gland. Clusters of these nodes are found in the neck, armpits and groins. It is here that the lymph is filtered and cleansed, so that the waste matter and harmful cells can be identified and removed by the body's defence system.

If the lymphatic system is not working correctly, or the vessels are not draining adequately, the fluid in the tissues builds up resulting in swelling. This is called Lymphoedema.

Lymphoedema can be divided into two groups, primary and secondary.

Primary Lymphoedema arises due to some failure of the lymphatic system itself - usually with the underdevelopment of the lymphatic system. It may develop without any obvious cause at different stages in life, but particularly in adolescence.

Secondary Lymphoedema is the result of some problem outside of the lymphatic system that prevents it working properly. Examples of secondary lymphoedema are:

The symptoms of lymphoedema vary between individuals and in severity. Affected areas of the body may display the following:

In severe cases of lymphoedema the skin may break under the pressure of the swelling, causing the lymph fluid to leak out onto the surface of the skin. This can lead to infection, often known as cellulitis. The skin becomes hot, red and painful, and patients may feel unwell and experience flu-like symptoms. Antibiotics are usually needed to clear up the infection.

Treatment for lymphoedema is designed to control these symptoms and consists of three main areas: