What is non-pitting edema?

Non-pitting edema is where there is not a persistent indentation to the skin. It normally affects the arms and legs. Non-pitting edema can occur in certain disorders of the lymphatic system such as primary (congenital) lymphedema, which is either a congenital absence of, or abnormalities in, lymphatic tissue, or secondary lymphedema, an obstruction or a disturbance of the lymphatic circulation that may occur in malignancies, infection, trauma, excision, or post-radiation fibrosis. Another cause of non-pitting edema of the legs is called pretibial myxedema, which is a swelling over the shins that occurs in some patients with hypothyroidism (underactive thyroid gland).