About lymph nodes and the lymph system

‘Lymph’ is fluid that forms naturally in the body. It moves through a network of tubes and glands (‘lymphatic vessels’ and ‘lymph nodes’) and drains into the bloodstream.

The lymph nodes are part of the body’s immune system and they filter lymph fluid. Filtering traps cancer cells, bacteria, viruses and other particles, which are then destroyed by immune cells.

Most people have at least a sentinel lymph node biopsy (removal of 1 to 3 lymph nodes) removed when they have surgery for invasive breast cancer.

When lymph nodes are removed, or damaged by radiotherapy, lymph fluid may stop flowing through the lymphatic system.

This can cause fluid to build up in the tissues and is known as ‘lymphoedema’.

You have lymph nodes in many places around your body. These include your:

• armpit (‘axilla’)
• chest
• neck
• groin
• abdomen.

Breast cancer cells can spread outside the breast. If they do, the first place they spread is often the lymph nodes in the armpit. This is why surgery for breast cancer often includes the removal of some lymph nodes.

Read about Surgery to the lymph nodes in the armpit ('axilla').