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What is lymphoedema
and chronic oedema?

Learn what chronic oedema is
including lymphoedema.

What is chronic oedema?

Oedema (or edema) means swelling. Chronic oedema is defined as swelling lasting for more than 3 months.[1]

All chronic oedemas represent a failure of the lymphatic system to cope with removing fluid sitting in the tissues.

The lymphatic system is responsible for tissue fluid reabsorption. In capillary exchange, pictured below, fluid comes out of the blood vessels into the tissue space and needs to be removed by the lymphatic system. All chronic oedemas show that the lymphatic system is either:

  • not coping with the volume of fluid needing to be transported in a given time period OR
  • not able to function correctly due to reduced transport capacity.

How do you know if oedema is present?

A simple clinical test is called the pitting test. When oedema is compressed it will “squish” away from the area leaving a fingerprint or divot. This is referred to as “pitting oedema.”

In the picture below a finger is applied to the lower leg and held for 30 seconds (left). If fluid is present, when the finger is removed a divot will remain which will gradually fill back up with fluid within a few minutes. The picture on the right shows that oedema is present.

James Heilman, MD. CC BY-SA 3.0

What are the types of chronic oedemas?

There are many types of chronic oedemas.

  • Lymphoedema – there is a problem in the lymphatic system. Fluid is the main problem. Over time fibrosis and fatty tissue become problematic. You can read more about lymphoedema on this page and here.
  • Venous disease – there is a problem in the venous system. You can more about venous insufficiency here.
  • Lipoedema – there is a problem in the lymphatic system. Fatty tissue is the main problem. You can read more about lipoedema here.
  • Heart failure and kidney failure – the organs of circulation are overwhelmed and bilateral lower limb swelling will result.
  • Palliative disease – severe cancers will block lymphatic flow and impact organ function.
  • Malnutrition or medication related swelling – malnutrition and certain medications will result in chronic swelling.
  • Dependent oedemas – post strokes or other neurological conditions, when the muscle pump is not working, swelling results.
  • Inflammatory conditions – some inflammatory conditions, such as rheumatoid arthritis, cause swelling.

A qualified lymphoedema practitioner can help with all forms of chronic oedema with the Casley-Smith method of Complex Lymphatic Therapy. The treatments may need to be modified. For example in palliative care Complex Lymphatic Therapy focusses on gentle movements and treatments designed to maintain comfort and reduce skin breakdown.

How do you know the type of oedema?

A proper medical diagnosis is important for any presentation of chronic oedema.

Specific tests can be performed. For lymphoedema, for example, special tests can be performed that can help confirm a diagnosis of lymphoedema such as lymphoscintigraphy, bioimepdance spectroscopy and lymphography (known as ICG or green lymphography).

It is important that special conditions, such as blood clots, organ failure, and inflammatory conditions, are not missed depending on the medical history. They are usually screened for through a thorough medical history, blood tests and medical imaging (such as MRI/CT and ultrasounds).

A doctor should always be consulted for any medical diagnosis.

What is lymphoedema?

Lymphoedema is type of chronic oedema caused when the lymphatic system is not working properly. The underlying main problem relates to the function of the lymphatic system:

  • too much lymph fluid is created which overwhelms a normal lymphatic system. This occurs in conditions such as venous disease, high blood pressure, heart and kidney failure. Initially the lymphatic system may be able to cope but it can become permanently damaged from ongoing overload and inflammation.
  • too little lymph fluid can be carried after the transport capacity has been reduced
  • a) Primary lymphoedema – Reduced transport capacity occurs when lymph vessels are not formed properly. The lymph fluid in a given body area cannot be moved adequately.
  • b) Secondary lymphoedema – Reduced transport capacity occurs when lymph vessels have been cut or damaged. The lymphatic system coped well before surgery or trauma. Afterwards, however the lymphatic system becomes overwhelmed. A secondary lymphoedema develops – meaning that the swelling is “secondary” to a known cause.

You can watch a video by Professor Piller explaining the two types of lymphoedema here.

A modern view of lymphoedema

Lymphoedema is an inflammatory condition.2

Ann easy way to understand the inflammatory processes in lymphoedema is to remember the three f’s:

  • fluid – initially lymphoedema starts as fluid building up in the interstitial space
  • fibrosis – overtime cellular activity become abnormal and cells such as fibroblasts start laying down too much tissue
  • fatty tissue – overtime cellular activity become abnormal and cells such as macrophages start contributing to fatty tissue deposition.3

Early detection is essential to pick lymphoedema up as early as possible. Lymphoedema can be detected at Stage Zero before there are physical signs of swelling!

How is lymphoedema an inflammatory condition?

Let’s explore this concept a little more in the work via the work of Mihara and colleagues.4

Pictures are shown below of patients with varying stages of leg lymphoedema and what happens inside lymphatic vessels at the same stage.

In Stage Zero lymphoedema, before there are signs of swelling, the lymphatic system looks healthy with great blood flow.

In Stage One lymphoedema, at early swelling, the lymphatic vessels becomes stretched. There is still great blood flow to the lymphatic vessel.

In Stages Two and Three lymphoedema, the lymphatic vessels go from being overstretched to contracted. They become full of fibrotic material. The vessels no longer have great blood supply and they cannot physically pump fluid as the vessel walls become too narrow.


1 – Keast DH, Despatis M, Allen JO, Brassard A. Chronic oedema/lymphoedema: under‐recognised and under‐treated. International Wound Journal. 2015 Jun;12(3):328-33.

2 – Ly CL, Kataru RP, Mehrara BJ. Inflammatory manifestations of lymphedema. International journal of molecular sciences. 2017 Jan 17;18(1):171.

3 – Ghanta S, Cuzzone DA, Torrisi JS, Albano NJ, Joseph WJ, Savetsky IL, Gardenier JC, Chang D, Zampell JC, Mehrara BJ. Regulation of inflammation and fibrosis by macrophages in lymphedema. American Journal of Physiology-Heart and Circulatory Physiology. 2015 May 1;308(9):H1065-77.

4 – Mihara M, Hara H, Hayashi Y, Narushima M, Yamamoto T, Todokoro T, Iida T, Sawamoto N, Araki J, Kikuchi K, Murai N, Okitsu T, Kisu I, Koshima I. Pathological steps of cancer-related lymphedema: histological changes in the collecting lymphatic vessels after lymphadenectomy. PLoS One. 2012;7(7):e41126. doi: 10.1371/journal.pone.0041126. Epub 2012 Jul 24. Erratum in: PLoS One. 2013;8(5). doi: 10.1371/annotation/6fff4d28-3f99-44eb-82d6-ccd885a1ba11. PMID: 22911751; PMCID: PMC3404077.

To learn more you can read the following blogs: