Why stop the swelling?
March 18, 2012 6:58 AM   Subscribe

Mrs. Musofire strained her ankle. Why are we icing it?

Mrs. Musofire strained her ankle yesterday, so I gave her anti-inflammatories and iced her ankle. But why do we try to stop the swelling? Isn't swelling the body's natural response to damage, bringing lots of nutrients and white blood cells and things to repair the damage?
posted by musofire to Health & Fitness (7 answers total) 2 users marked this as a favorite
 
Swollen soft tissues get less oxygen, which inhibits healing. It also hurts.

Don't confuse a natural response with a medically "good" one; swelling as a response may make evolutionary sense for conditions we aren't faced now with, such as our modern antiinflammatories and ready access to ice.
posted by ellF at 7:09 AM on March 18, 2012 [2 favorites]


Isn't swelling the body's natural response to damage, bringing lots of nutrients and white blood cells and things to repair the damage?

Bleeding is the body's response to being cut, and yet we try to stop the bleeding. Everything that happens to you during a cold is your body's natural response to an infection, and yet we try to curb these symptoms. There are many involuntary reactions that we interfere with to bring about to make us more comfortable or hasten the healing process.
posted by hermitosis at 8:11 AM on March 18, 2012


Best answer: Inflammation is actually an incredibly complex biological process involving multiple body systems. In response to an injury, the local vasculature around the site of injury and the immune system work together to increase blood flow and the number of white blood cells in the region. This is useful, and through a number of processes can lead to tissue repair.

However, inflammation is by no means a passive response to injury. It is actually actively maintained by a complex network of biological signals, and it can also be actively shut down by the body. When inflammation lasts a long time, it not only hurts but can be damaging to tissue. This can occur for many reasons - you could form scar tissue instead of healing the injury, the presence of too many white blood cells could be releasing chemical signals causing the inflammation to continue, etc...

Basically, inflammation is very complicated and while it is mission-critical in the acute healing of an injury, over time it can cause painful long-lasting problems, so it's best to stop it short because the body's mechanisms of ending inflammation aren't by any means foolproof.

(I'm a Ph.D. student in a department that happens to have a heavy focus on inflammation, but it's not my area of research.)
posted by Cygnet at 9:23 AM on March 18, 2012 [5 favorites]


Best answer: I'm a runner with a minor knee injury and I just posed more or less this same question to a doc. His answer was that when you are injured, your body's inflammatory response summons all sorts of immune system responses to fight off potential infection. This is extremely helpful if you were cut or stabbed, but mostly not needed if you just suffered internal injuries. Therefore, most of the cast of thousands that your body brought to the site aren't effective and all of the excess fluid just serves to make the internal injury worse by putting pressure on already damaged tissue. He admitted that this was oversimplified (some of the response is still helpful at clearing out damaged cells) but remained steadfast that the vast majority of the response was aimed at defending against infection. There was more about NSAIDs compared to steroids and something about prostaglandin, but I kinda spaced out by that point. I'm not sure if he was saying it doesn't entirely shut down the process or what, but he was adamant that for sprains and strains, fighting the swelling was the bomb.
posted by Lame_username at 11:29 AM on March 18, 2012


Think in these terms. Your body has many systems that were exquisitely designed to fight problems that we no longer face. Your appendix is a good example. I believe that swelling at the site of an injury was necessary before there were other mean (such as ice, NSAIDs, etc.) but are no longer necessary. Our bodies will take millennia to catch up. I also believe that ice is only effective for the first day of two and that, after that mild heat will help.
posted by Old Geezer at 11:54 AM on March 18, 2012


I believe that swelling at the site of an injury was necessary before there were other mean (such as ice, NSAIDs, etc.) but are no longer necessary.

But both the ice and the NSAIDS (non-steroidal anti-inflammatory drugs) target the inflammatory response. No inflammatory response, no need for ice or NSAIDS.

I'm a massage therapist and I have noticed a huge difference in clients' pain levels if we ice inflamed areas, and ice right after deep massage work. I'm not so sure whether it heals better, but pain levels are night and day.
posted by parrot_person at 6:58 PM on March 18, 2012


Here is a little review about icing from the British National Council for Osteopathic Research.

In addition, if you are following the model of vasoconstriction helping with the symptoms, it is important not to ice for too long. After around twenty minutes, the body reacts to the cold and vasodilates instead, causing increased blood flow, and increasing the swelling - the opposite effect!
posted by fizban at 4:06 AM on March 19, 2012 [1 favorite]


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