Good question! lymphedema
is a build-up of lymph, which is a yellowish to milky fluid thatcomes from your blood.
If you took a tube of blood and let it sit, the cells would settle to the bottom and a yellow fluid would float to the top, called plasma. Lymph is very similar to plasma. As blood flows through capillaries that get smaller and smaller, lymph is squeezed out into your tissue.