In a normal (ideal) scenario, where everything is functioning properly, there is always constant fluid movement in our tissues. Fluid comes into the tissues from the blood capillaries and is taken up by the lymphatic system, filtered and then returned to the blood stream.
In lymphatics, when talking about this fluid movement we often refer to the “bath tub” analogy as it gives a good visual reference for learning.
So, using the bath tub example, imagine the bath tub is our tissues. All the cells of our body are in the bath tub and they’re surrounded by a warm watery solution.
Imagine the blood capillaries are the tap that is constantly filling the bath, refreshing the watery solution and delivering nutrients to the cells, and imagine the lymphatic system is the drain. The drain is essential to maintain the water level of the bath and stop a disastrous overflow. It’s when the bath tub overflows that we see swelling. The medical term for swelling is “oedema”.
Under normal circumstances, the ‘tap’ is running at just the right flow rate to keep the water in the bath constantly refreshed and the ‘drain’ is operating at just the right pace to maintain the water level of the ‘bath tub’.
Interesting fact …
The lymphatic system has a functional reserve of 80%. This means under normal circumstances, it’s only operating at 20% of it’s transport capacity. This is one of the body’s safety mechanisms. By the time swelling is visible … well, think iceberg.
Unfortunately, sometimes circumstances aren’t always ideal and the ‘tap’ runs too fast for the ‘drain’ to keep up or, sometimes there’s a problem with the ‘drain’.
Some circumstances that can cause the tap to flow too fast and result in too much fluid coming into the tissue bath could be heart or kidney problems. Some medications can cause our blood vessels to become more permeable which may also turn the tap up resulting in an increase in fluid coming into the tissues. Oedema also occurs after trauma or injury and is part of the body’s normal inflammatory response. This is known as a Dynamic Oedema and is a low protein oedema. It is important to understand the cause of swelling before attempting to treat it.
Oedema formation isn’t always because there is too much fluid coming into the tissue bath. Sometimes it’s due to the drain not working properly so the fluid isn’t being taken out of the tissues fast enough. When the oedema is due to a disfunction of the lymphatic system it is called lymphoedema.
Lymphoedema is a high protein oedema and can be divided into Primary and Secondary Lymphoedemas.
Primary Lymphoedema is where the lymphatic vessels and/or lymph nodes haven’t developed properly. It is more common in women than men and may not appear until puberty or during pregnancy.
Secondary Lymphoedema is where the lymphoedema has occurred as a result of damage to the lymphatic system, often following surgery or radiotherapy to treat cancer.
There are stages of progression in Lymphoedema. The International Society of Lymphology (ISL) has defined a three stage scale, with recognition of a latent or sub-clinical stage, for classifying the stages of lymphoedema progression. There may be more than one stage presenting in a lymphoedematous limb at any one time.
Stages of Lymphoedema Progression
Stage 0 (Latent/sub-clinical)
Lymph transport is impaired but there is no swelling yet. People “at risk” may be included in this stage.
- Impaired lymph transport but swelling is not yet evident
- the lymph system is still working
- Best time to take action. ACT NOW!!
Stage I (Mild)
Tissues still feel soft and the swelling goes down over night or with elevation.
- slow, invisible changes in the tissue
- may not be visible
- may feel heavier than unaffected side
- the lymph system is still working
- Best time to take action. ACT NOW!!
Stage II (Moderate)
Tissues are getting harder and heavier and some minor skin changes may now be noticed.
- visible swelling, limb enlargement
- pitting oedema – pressure will leave a pit mark, this means there is still fluid around
- few skin changes, skin still looks normal but may be a bit dry
- progression of tissue and skin changes
- thickening in tissues
- pitting is flatter and tougher
- The limb can feel hot. There may be chronic inflammation.
Stage III (Severe)
Tissue feels very hard and there are major skin changes. This is very hard to reverse.
- Thick, hard skin with permanent folds
- hard to create a pit with pressure due to the hardness of the skin and tissue
- papillomas (warty looking growths)
- lymphatic cysts and fistulas (leak fluid)
- nail changes – thickening and yellowing of nails
Although there is no cure, if diagnosed and treatment is commenced early, it is possible to live well with Lymphoedema. Read more about living well with Lymphoedema here …
Early intervention will always deliver the best results.
Further reading and references:
- Australasian Lymphology Association (ALA) – What is Lymphoedema?
- International Society of Lymphology (ISL) Consensus Document
- British Lymphology Society (BLS) – Lymph Facts: What is Lymphoedema? Resource to support teaching on lymhoedema (handout)