Lymph nodes

Lymph nodes are small, bean-shaped organs in the lymphatic system that play an important role in the immune system. They filter lymph, a fluid that carries waste products and pathogens out of the body. Lymph nodes contain immune cells that recognise and fight pathogens.

Lymph nodes are found all over the body, especially in the armpits, groin and neck. They often swell when the body is fighting infection, which is often perceived as a sign of illness.