Causes of lymphoedema - Lymphoedema

There are 2 types of lymphoedema, primary and secondary lymphoedema. They have different causes.

Primary lymphoedema

The cause of primary lymphoedema is genetic. Changes (mutations) in certain genes can affect the development of the lymphatic system.

This means the parts of the lymphatic system that drain fluid do not work well.

Primary lymphoedema often runs in families. But not every child born to someone with the condition will develop it.

Primary lymphoedema is rare. It may affect around 1 in 6,000 people.

Secondary lymphoedema

Secondary lymphoedema happens when your lymphatic system is damaged.

The most common causes include:

• surgery for cancer
• radiotherapy
• infections
• inflammation
• venous diseases - problems with your veins
• obesity
• trauma and injury
• immobility

Surgery for cancer

Some cancer treatments can include surgery to remove parts of the lymphatic system, such as lymph nodes.

Lymph nodes are pea-sized lumps of tissue that contain white blood cells. They help remove bacteria, viruses and other causes of infection from your body.

Your surgeon will try to limit damage to your lymphatic system. But sometimes this is not possible. There's a high risk of having lymphoedema if you need to have some lymph nodes removed.

Cancers where this may happen include:

• breast cancer
• skin cancer (melanoma)
• gynaecological cancers - such as cervical cancer and vulval cancer
• genitourinary cancers - such as prostate cancer or penile cancer

Radiotherapy for cancer

Radiotherapy uses controlled doses of high energy (radiation) to destroy cancerous tissue. But it can also damage healthy tissue.

If there are cancerous cells in your lymphatic system, you may need radiotherapy to destroy them. This treatment can damage the lymphatic system.

Infections

Infections such as cellulitis and lymphatic filariasis can cause lymphoedema.

Cellulitis is a bacterial infection of the dermis (deep layer of skin). Severe cellulitis can damage the tissue around the lymphatic system.

Lymphatic filariasis is a parasitic disease caused by microscopic worms. The adult worms live in the human lymphatic system and block lymph drainage.

Lymphatic filariasis is a common cause of lymphoedema worldwide. But it's not a high risk in Ireland.

Inflammation

Conditions where your body tissue is red and swollen can damage the lymphatic system.

Common conditions that can cause lymphoedema include:

• rheumatoid arthritis
• eczema

Venous diseases

Venous diseases are diseases that affect blood flow in the veins. They can cause lymphoedema in some people.

Abnormal or damaged veins can cause fluid to overflow from the veins into the tissue spaces. The excess fluid becomes too much for the lymphatic system to drain.

Some venous diseases that can cause lymphoedema include:

• deep vein thrombosis (DVT) - a blood clot in one of the deep veins in the body
• varicose veins - swollen and enlarged veins

It's important to wear compression stockings if your GP recommends them. This keeps the fluid under control and reduces the risk of ulcers.

Obesity

Obesity can cause swelling and lymphoedema. Carrying extra weight may affect the flow of fluid in the lymphatic channels.

Weight loss is an important part of treatment. Even starting to lose weight can make a big difference.

Trauma and injury

In rare cases, accidental injury to the lymphatic system causes lymphoedema.

For example, it can happen after a road traffic accident if you have severe bruising or soft tissue loss.

Immobility

Muscle activity from movement or exercise helps massage fluid into and along lymphatic vessels.

If you cannot move around much, the fluid in the lymphatic system does not flow properly. This can lead to lymphoedema.

You may be at risk if you have limited mobility for a long time because of an illness, nerve damage or arthritis.