Two Main Types - Primary and Secondary Lymphoedema
Lymphoedema is a life-long chronic condition, in which excess fluid, known as lymph, collects in tissues causing a swelling, known as oedema. The swelling is caused by a blockage of the lymphatic system due to the absence of lymph vessels or a dysfunction of the lymphatic system.
Primary lymphoedema is when the lymphatic system has not developed adequately, or is not functioning as it should, at birth. When a lymphatic system is no longer able to cope with the demands placed on it, primary lymphoedema can develop. It is called 'primary' as the cause of the impairment is to be found in the structure of the lymphatic system itself. There are five main classifications of primary lymphoedema1 and there are many known syndromes that have been linked with primary lymphoedema e.g. Noonan Syndrome, Prader Willi, Yellow Nail Syndrome, Turner Syndrome
- Congenital onset (e.g. Milroy’s disease) - lymphoedema is noticeable at birth or presents before the age of one
- Disturbed growth / cutaneous manifestations / vascular anomalies (e.g. Klippel-Trenaunay Syndrome, Proteus Syndrome)
- Systemic / visceral involvement: pre-natal or post-natal onset (e.g. generalised lymphatic dysplasia)
- Syndromic (e.g. known / unknown syndrome) – refers to a group of various abnormalities, one of which is lymphoedema
- Late onset (e.g. Meige) - lymphoedema presents after one year of age
Causes of secondary lymphedema include:
- Surgery (e.g. lymph node surgery) / radiotherapy / chemotherapy: removal of lymph nodes, often associated with cancer, can damage the lymphatic system and radiation treatment can impair lymph flow
- Malignant tumours: tumours may put pressure on lymph vessels, decreasing fluid flow
- Trauma (e.g. crushing injury, burn, scarring, extensive wound): sustaining an injury can interfere with lymph flow
- Infection: recurrent infections can cause a failure of lymph vessels
- Chronic venous disease (e.g. varicose veins, leg ulcers): this condition puts extra pressure on the venous and lymphatic systems and subsequently overloads the lymphatic system
- Obesity: an increase in lymph, and often time-increased pressure on lymph nodes, can impair lymph flow
- Self-induced: such as a tourniquet being used which impairs lymphatic and venous flow
- Immobility / reduced muscle activity,(e.g. stroke / paralysis): leads to fluid build-up and an overloading of the lymphatic system
- Filariasis: a parasitic disease found mostly in third-world countries which impairs the lymphatic system
There are other types of oedema which should not be forgotten.
Often confused with lymphoedema, lipoedema is an adipose tissue disorder or abnormal accumulation of fatty tissue. It affects mostly women, often developing around the time of a hormonal change (i.e. puberty, pregnancy or menopause). The condition leads to tissue enlargement most commonly around the legs, hips and / or buttocks. Unlike lymphoedema, the enlargement usually stops at the ankles and the feet are spared. However, it tends to be in both legs. It mostly affects the lower limb but can develop in the arm (the hands are usually spared). It often leads to a sensation of the limbs being ‘heavy and tight’ and the skin may be tender to touch, cooler than unaffected areas, sensitive and/or bruise easily. Despite dieting or increasing physical activity, the volume of the limbs does not decrease and there is a distinct disproportion between the limbs and the trunk. Those who have had lipoedema for many years often develop a lymphatic component, as the fatty tissues tend to obstruct lymphatic drainage. This is known as lipo-lymphoedema. The surface of the skin is more uneven, there may be ridges of fat under the skin, the limb is more distorted and mobility may be inmpacted. The foot can become swollen.
This condition results in both the venous and lymphatic systems not functioning adequately due to an underlying venous problem / disease and results in a swelling. When valves weaken or there are abnormalities in the venous walls, blood can flow backward and increase the pressure in the veins, known as venous hypertension. If venous hypertension is sustained over time, the vein walls stretch and the valves no longer close. This further increases hypertension which can lead to a pooling of blood, discomfort and varicose veins. The common signs are staining of the skin, spider veins and varicose veins. A swelling occurs when the increase in lymphatic flow to the area is much greater than the lymph transport capacity.
Lymphoedema is most often seen in the arms and legs but it can also develop in other areas of the body. For more information, click here.
1 Source: F Connell, G Brice, S Jeffery, V Keeley, PMortimer, S Mansour (2010) A new classification system for primary lymphatic dysplasias based on phenotype Clinical Genetics 77: 438–452.