The lymphatic system is one of the body’s natural defences against infection. It includes a network of tiny tubes like blood vessels, which pass through almost all the tissues in the body. These vessels carry a clear watery fluid called lymph.

This lymphatic fluid contains infection-fighting cells called lymphocytes. Along this network are hundreds of small bean shaped glands called lymph nodes. Their job is to filter the lymphatic fluid for foreign particles as it passes through. They also allow the lymphocytes to interact so that they can function to protect the body against infection.

Lymph nodes can be found in groups throughout the body such as in the neck, armpits and groin. Sometimes you may become aware of these glands if they become swollen or enlarged. More of these lymph nodes are found grouped together in the chest and abdomen. Other parts of the lymphatic system include the spleen, thymus, tonsils and bone marrow.