Causes of Lymphoedema

What causes lymphoedema?

In most cases the cause of lymphoedema is damage to the lymphatic vessels which can follow surgical procedures, radiotherapy or other conditions such as certain infections. This type of lymphoedema is termed 'secondary' lymphoedema.

In some cases there is no obvious cause and the lymphoedema has developed because of a developmental abnormality of the lymphatic vessels. Sometimes the swelling is present at birth but in many cases the swelling does not develop until later life. This form of lymphoedema is known as 'primary' lymphoedema. A number of genetic causes for primary lymphoedema have now been identified.

What kind of lymphatic abnormalities can cause lymphoedema?

A number of different types of abnormality of the lymphatic vessels can cause lymphoedema.

First of all, the lymphatic channels may be absent (aplasia). Sometimes the lymphatics are few in number (hypoplasia). There may be an excessive number of abnormally functioning lymphatics (numerical hyperplasia) or there may be dilated vessels (megalymphatics) which are often associated with lymphatic fluid collections or leaks such as chylothorax (lymph in the chest), chylous ascites (lymph collection in the abdomen).

Rarely, the lymph can actually leak out of vesicles or 'blisters' on the skin, mucous membranes or bowel.

Finally, the lymphatics may be obstructed secondary to an inflammatory-type process in the lymph nodes draining an area of the body. This causes the lymph flow to be slowed or halted.