Lymphedema is a health condition involving swelling of the lymph nodes, usually in the arms or legs, due to inadequate drainage of the lymph fluid from the body.

The lymphatic system plays an essential role in the body by circulating of lymph throughout the body to collect foreign bodies such as bacteria, viruses and waste products. The waste products can be filtered out by lymphocytes that are designed to fight infection in the body.

There are primary and secondary cases of lymphedema, depending on if it was caused by another underlying health condition.

Primary Lymphedema

Primary lymphedema is rare and usually an inherited condition that arises as a result of abnormal development of the lymphatic system, including:

• Milroy’s disease, also known as congenital lymphedema, begins in infancy and involves abnormal function of the lymph nodes.
• Meige’s disease, also known as lymphedema praecox, usually initiate around the age of puberty or during pregnancy.
• Late-onset lymphedema, also known as lymphedema tarda, is a rare condition that involves the presentation of symptoms after the age of 35.

Although the pathogenesis of primary lymphedema is not entirely known, it is thought to be caused by gene mutations that affect the development of the lymphatic system.  This result in a reduction of the individual’s ability to drain the lymph fluid as required.

A genetic link has been suggested due to the high prevalence of individuals with the condition that have a close relative with the condition. No specific genes are currently associated with the condition, however, and there is scarce evidence to suggest that offspring of affected individuals are at risk.

Secondary Lymphedema

Secondary lymphedema is the most common type and occurs as a result of a condition or procedure that has caused damage to the lymphatic system.

• Surgical procedures involving the removal of or damage to the lymph nodes or vessels may lead to lymphedema.
• Radiation therapy can cause scarring and inflammation of the lymphatic system.
• Cancer cells may obstruct lymphatic vessel and result in lymphedema, particularly for tumor growth in close proximity to the lymph node or vessels that may block the flow of lymph fluid.
• Infection of the lymph nodes can also restrict lymph flow and lead to swelling and scarring of tissue. Parasitic infections with the same effect are particularly common in tropical and subtropical regions.
• Inflammatory conditions such as rheumatoid arthritis, dermatitis and eczema may cause tissue inflammation and damage to the lymphatic system.
• Cardiovascular diseases that affect the circulation of blood throughout the body place patients at higher risk of experiencing lymphedema. This is most evident in patients with deep vein thrombosis, venous leg ulcers and varicose veins.
• Injury or trauma to the skin that causes significant scarring may damage the lymphatic system and increases the risk of lymphedema in rare cases.
• Immobility reduced the movement of lymph fluid and drainage, thereby increasing the risk of lymphedema.

Secondary lymphedema is particularly common among patients that have had treatment for cancer that may have damaged the lymphatic system. The symptoms of this may present shortly after the procedure or be delayed for several months or years.

References

• http://www.mayoclinic.org/diseases-conditions/lymphedema/basics/causes/con-20025603
• http://www.medicalnewstoday.com/articles/180919.php
• http://www.nhs.uk/conditions/Lymphoedema/pages/causes.aspx
• http://my.clevelandclinic.org/services/heart/disorders/Lymphedema/Heart_overview