Inflammation vs Swelling

One is helpful, one is a hindrance!

Mention the word inflammation and the general connotation is usually negative – it’s bad, we want to stop it, how can we minimise it, should I use anti-inflammatories? So it may surprise some to know that inflammation is actually good – to a degree! Added to this, swelling and inflammation are not interchangeable words, and I’ll explain the difference as we go along.

Firstly, inflammation: inflammation is a crucial process in the body that has the following critical functions:

1.            To defend the body against alien substances

2.            To dispose of dead and dying tissue

3.            To promote regeneration of tissue

In other words, inflammation is the process which helps our body to heal following injury, trauma, and tissue damage. It is a vital process and not one that we want to necessarily be desperate to inhibit or reduce. Inflammations happens for a reason – because there is a problem that needs fixing. Our brains are incredibly smart and know when to switch the inflammatory process on (as soon as tissue damage occurs), and also when to ramp the process down, and eventually switch the process off (when tissue healing has occurred). Do we really want to overcome our body’s natural healing process by taking anti-inflammatories (for example) as soon as we get hurt? Possibly not – letting nature take its course may be the best thing we can do!

What about swelling? Swelling is one of the five major signs of inflammation (redness, heat, pain, loss of function being the others). Swelling is NOT inflammation! And swelling can occur in the absence of inflammation – take for example the commonly experienced swelling in your feet and ankles after a long plane trip, or spending hours on your feet. This swelling is not due to inflammation, it has an entirely separate cause.

In many cases, swelling is the result of bleeding from the acute injury or trauma. Prolonged swelling (often called oedema) has many harmful effects: swelling may result in slower blood flow around the injury and less oxygen being delivered to both the damaged cells and the nearby healthy cells, causing even more damage. Ongoing pressure and secondary damage from swelling may result in a prolonged inflammatory process, and this is where problems can arise. Swelling needs to be minimised.

The summary of this is that inflammation is not only good, it is a necessary component of healing. Swelling is an unfortunate by-product of injury and inflammation, but persistent swelling may in turn cause inflammation to continue beyond the helpful phase. If Inflammation is essential for healing to occur, as outline above, we really don’t want to be diminishing the inflammatory response which would just delay healing; however limiting the swelling may be advantageous. This helps to explain why, in many cases, anti-inflammatory medication is not commonly used in acute injury (because we need the early inflammation) but may be used as symptoms persist beyond optimal time periods. Inflammation does become an issue when, for whatever reason, there is an excessive inflammatory response, or the inflammatory process gets stuck in the “on” position despite tissue being healed! This can be the case in conditions like Rheumatoid Arthritis and other auto-immune disorders, (or when injuries are poorly managed) where the body continues to attack itself in a self-perpetuating fashion: tissue damage leads to inflammation, which leads to more tissue damage which needs to more inflammation…and so on. In cases like this, an anti-inflammatory approach is essential.

And this brings me to the interesting topic of ice! For years ice has been the immediate priority following acute injury, and the general purpose has been to reduce swelling. Research tells us however that swelling is only influenced if we reduce metabolism and for this to happen, ice would need to reduce the tissue temperature at the injury site down to between 5 and 10 degrees – at depth, not on the surface. No study has been able to demonstrate this at a depth of even 2cm below the skin tissue, and there is no evidence for the ability of ice to reduce metabolism in the human tissue. What ice does definitely do is reduce pain, so perhaps the best use for ice is pain reduction! And pain relief is not always just for the purpose of comfort alone – less pain means more normal movement and function of the injured area, and often movement is necessary for healing.

Personally, when swelling is involved (or there is a concern that swelling will occur), I believe compression, elevation, and gentle active movement of the area provide better management of the swelling than ice. Whilst I would always ice immediately after injury (for pain relief) I think compression is the most critical intervention to employ post injury. Compression reduces the available space for swelling (the undesirable side effect) to collect, whilst not inhibiting inflammation (the desired side effect). Keeping the injured area moving in a very controlled manner (but you must seek advice from your physio to make sure this is safe first) can also have a great impact on minimisation of swelling.

What does this all mean?

In a nutshell, the inflammatory response is an essential part of healing, and consideration should be given before any attempt is made to stop it. One of the main goals in the acute treatment of an injury and during rehabilitation is to limit and then aid the removal of swelling, and compression (and elevation) achieves this with greater success than ice application. And on a final note, anti-inflammatories can also have a blood thinning effect which you probably don’t want to do if the injury involves some internal bleeding – so to all those athletes that pop an “anti inflam” the minute they are injured, you may actually get better healing by letting your body take control.

Anthony Lance

SSPC Physiotherapist

References available on request.