The lymphatic system consists of channels and glands that help to fight infection and get rid of excess fluid. Lymphoedema occurs when your lymphatic system is not working properly and fluid builds up under your skin, causing swelling.
There are 2 types of lymphoedema: primary and secondary. Primary lymphoedema (also known as Milroy disease) occurs when your lymphatic system is badly formed. This genetic type can be evident at birth or can appear later.
Secondary lymphoedema results from an event such as an infection, an injury, cancer treatment or a lack of movement of the limbs resulting in a damaged lymphatic system. This then affects fluid drainage.