Swelling inhibits healing, so why does our body do it?

If swelling in the injured area gets in the way of healing, then why does our body do it? Our body is perfectly capable of healing a sprained ankle in several weeks, if we control the swelling. If we don’t control the swelling, it could take much longer, and might never heal as well.

**Now, I am not asking why we swell, but really why we swell so darn much. I’m sure some swelling could be good…

Why does our body shoot itself in the foot by overreacting like this? I can’t recall many things that our body does that is really bad for it’s own well-being…

Or maybe there is a good reason to flood the injured area with blood to the point of practically bursting the skin?!

IANAD, and this is mostly a WAG:

I think that your body doesn’t know the nature of an injury, all it knows is that SOMETHING is wrong, and so it sends in all it’s resources to investigate. Your immune system kicks in, your blood clotting mechanisms do as well, etc etc. The fact that a sprain, for example, is better off WITHOUT this response is not something your body can know, and so it’s reaction is the same than if you had a large cut or other injury which does need these things. As long as an attempt to heal is made, it doesn’t matter whether the sprained joint is as good as new or not - it will keep you alive, and that’s what; s important.

Another guess. I think that in the case of a broken bone, swelling does help. The swollen tissue will tend to hold things in place so that the bone can heal better. Like a natural cast.

I Am Not A Doctor? and (I’ll) Wager A Guess?

Great question and sounds llike a good answer. The immunes system does the same thing in an anaphylactic reaction. I was in the mountains of Mexico when I ate what had to be, though I had no memory of it, my second guava. Darn near died.

Sorry for my bad habit of not previewing my posts. It is “immune system”.

Yes, but the difference between swelling and anaphylactic shock/reaction is that only some people have those types of reactions, whereas everyone swells profusely when they facture a bone or sprain a joint. Allergies are an example of overreaction but not everyone has them.

basically expanding on whatmnemosyne said:
Swelling and inflammation is the result of leukocytes and acute phase proteins migrating to the area of injury or infection. It has nothing to do with your body “knowing” or not knowing the manner of injury. Whether infection or injury, tissue and cell necrosis, or death, results, lysis occurs and intercellular contents spill out of the cell, setting off a complex reaction which eventually results in chemoattractants being released and drawing white blood cells, platelettes, acute phase proteins etc. to the area. This is the beginning of the healing process. Platlettes and clotting factors stem bleeding, macrophages ingest the dead cells, break them down, and remove them from the site, they also remove the “spilled” intercellular components. At the same time leukocytes release histamines and other chemicals which act on the vascular system so more cells can more easily migrate to and from the area of injury. This also increases red blood cell flow to the site. Swelling is a necessary byproduct of the body’s reaction to tissue damage. Anaphylaxis on the other hand is an extreme form of immediate hypersensitivity (allergy), which is the result of an atopic person being sensitized by a first exposure to an allergen, the person develops antibodies to the allergen as well as memory B cells, which are sensitized and stand ready to multiply and produce much greater amounts of antibody much more rapidly should the host be challenged with the allergen again. The second response is much more pronounced. More about anaphylaxis here.

So, why do we interrupt it by putting cold on the injury? That’s what this thread is about…

I can’t add anything to the substance of this thread, but since nobody answered, yes IANAD = I am not a doctor, IANAL = not lawyer, etc… WAG = Wild Ass Guess.

Can we give this another whirl?

We swell, we try to stop it, we know stopping it helps, why does our body do it so full fledged, as if it was good? Pretty simple premise, no simple answer, I presume…

Isn’t there a doctor in the house? :smiley:

I’m still unclear as to why everyone thinks that reducing the swelling helps speed healing. I was under the impression that icing was to reduce the pain associated with the swelling.

i also dont know where you’re getting it that swelling slows healing ???

increased blood flow to the affected area speeds healing.

Yes, my first though was “swelling DOES speed up healing”, but after reading some of the answers doubt began to emerge.

Now that some people seem to agree with me, I feel confident to say that swelling is part of the body’s immune response. Swelling is when the capillaries dilate and become “leaky”, allowing white blood cells to diffuse into the affected area and fix the problem. Now, why we try to slow down the swelling is because it is usually accompanied by pain - we choose to heal slower for the sake of killing the pain.

It’s quite the same story when we have a fever or a cold. We take medicine that slows the symptoms of the sickness for the sake of comfort, it does not, however, accelerate healing.

Man, I am really astounded by this. You mean to tell me that stifling swelling with a cold pack makes our healing process take longer and actually makes it less effective???

This is big news to me. This is huge. I absolutely cannot believe that this became such an amazingly widespread practice just to reduce the pain?! Unbelievable. Please, Dopers, tell me it ain’t true!!!

Thinking like this presupposes that by virtue of having arisen through evolution, our physiology is somehow optimized. This is false. Things happen in us the way they do because by happening this way, enough of us survive to make a surplus of human babies. It doesn’t have to be any more optimal than that.

We know that inflammation is part of healing but to presuppose that an optimum amount of inflammation occurs with each (or any) injury is bubkis (?sp). A dramatic example of inflammation waaaay out of control occurs in the setting of overwhelming systemic bacterial infections (sepsis). In this situation, one’s immune response is too powerful, and has toxic effects, often leading to death.

A counterpoint to this is a common situation wherein a paucity of inflammation allows persistent viral infection, as is the case in human papilloma virus (HPV) infection. HPV is the causative agent of the common wart. For reasons which are not completely understood, our immune system tends to ignores HPV, allowing it to happily grow on our hands, feet, and naughty bits. This illustrates the point again that our physiology does not select the “right” amount of inflammation in some circumstances.

Reducing inflammation after injury (by icing or by taking NSAIDS) does not slow recovery in any study I’ve seen. Use of a more potent anti-inflammatory, such as prednisone, however, strongly inhibits healing.

To return to the OP, some inflammation and some pain is likely a good thing. The inflammatory response participates in tissue repair while the pain prevents unwise use of a damaged limb or member. Why is the response sometimes too much for our liking? As I said earlier, it’s unlikely that our bodies select a magically perfect level of inflammation to deal with each insult. As flesh and blood creatures, we dislike the sensation of pain. And furthermore, as intelligent, industrious creatures, we develop means to reduce the accompanying discomfort of this inflammation.


I know this thread is old but I feel that the information is relevant and would benefit from being updated.
Putting ice on injuries could slow healing:

This research is by no means over and further studies will continue to develop this idea into a workable understanding.
My take on icing an injury is that moderate intermittent application is ideal for both relief of discomfort and optimal healing.

On a side note, the reason I started researching this, other than having an injury which has swelled, was that in cryobiology lower temperatures inhibit cell activity and growth, which is what healing would logically require. It seems simple to me. All matter slows when relieved of energy and, conversely, accelerates when energy is acquired. Therefore, the healing of an injury must, significantly or not, slow when chilled.

Of course there must be other factors affecting swelled vs deflated healing outside of temperature. Are relevant components of healing allowed to act more efficiently when whatever is causing the swelling is gone?
All feedback appreciated.

I haven’t read your link and don’t recall seeing this thread in its first incarnation. That being said, it makes sense that cooling would impair healing (as a general rule). Why? - the cooling causes the blood vessels to constrict (to conserve heat) and thus will lead to a reduction in the delivery of white cells, antibodies, reparative cholesterol, etc., to the affected area.

OTOH, for some injuries, there may be a benefit in cooling if the cooling leads to a reduction in those processes that are furthering the damage, e.g. overly exhuberant inflammation (leading, for example, to so much swelling that the pressure in the injured area increases to the point of preventing blood to enter), apoptosis, etc. This underlies the rationale for cooling people with various brain injuries (with the skull being a closed space where pressure can build up).

Man, is this thread the Twilight of the Banned, or what?

It is common to see medical studies in the news written up as though the information is “the first”, and “new study shows”, when in fact that is not the case at all. Researchers are always looking for research money and want their study to seem important. Furthermore, the write-up further misrepresents the study. It has long been known that some inflammation is important for wound healing. Over the last say 40 years icing a swelling trauma wound remains the same, but the amount of time has been reduced from continual to on and off for 15 or 20 minutes to about 15 minutes each hour, and currently the advice is 15 minutes every 4 hours. The idea behind the cooling is to lessen the amount of blood and fluid loss from injured cells and not inhibit the inflammation response which is important for the healing process. Ice is only used for the first few days and heat may be used after that to increase blood circulation to the injured area.