Why do we elevate injuries to promote recovery? If this is the correct thing to do, why does the body send more blood to the injury?


Why do we elevate injuries to promote recovery? If this is the correct thing to do, why does the body send more blood to the injury?

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Elevating injuries makes it easier to recirculate the blood at the injury site. Excess blood can cause unwanted swelling which could worsen the injury. Plus, blood at a lower injury site has to fight against gravity to go back to the heart. Elevating the injury site above the heart allows blood to easily flow back with gravity.

Blood to the site is not greatly affected by elevation since it’s already at a high pressure when pumped by the heart.

It’s to reduce the swelling, which causes more pain.

The heart pumps blood out through the arteries, a high pressure system.

The veins return the blood passively, along with the lymph system, helped along by muscles, and by gravity if it’s above the heart. So, if an arm, for instance, is injured, with leaky vessels pouring out white cells – creating more congestion on the lymph system, then raising that arm above the level of the heart, improves return flow.

When a part of the body is swollen, there is a lot of space between cells full of fluid and debris, making it more difficult for the arterial system carrying oxygen and nutrients, to reach all the cells. Elevating that arm helps drain it back into the system.

Injury repair in the body needs both the circulatory system and the lymphatic system, both of which are effected by gravity. So by elevating the injured area, there is less resistance on these system. Likewise, if something is bleeding, you should elevate it above the heart trying to get it to stop bleed quicker.

I think most people have missed the point that the innate immune response in the body in the form of inflammation is non specific. E.g. if there is a bacterial infection in a tissue or if you’ve just bumped your toe hard the initial inflammatory response is the same and it is not always helpful in the case of some injuries e.g. if you dropped something on your foot. This is because some of the inflammatory cells that come such as neutrophils can release enzymes that can further worsen the tissue

As such we compress the areas and ice it and elevate it to reduce this response

As others have said, elevation is more about helping blood leave the site because it rarely has trouble getting there, so our body is doing the right thing and we’re just helping it along.

There are lots of cases though, where our bodies really don’t do the right thing to make us better. We didn’t evolve with modern life and medicine in mind, so our bodies are operating under a different set of rules.

A common example is healing from cuts and scrapes, an open wound is a dangerous source of potential infection, so we need heal it as quickly as possible. Forming normal skin is a slow and difficult process though, so instead you scab over to protect the wound, then form scar tissue to properly seal it up. But throw wound dressing on there to keep it protected and your body will heal up with much less scaring. Our body doesn’t need to worry about sealing up as soon as possible, because we can do that; nor does it need to worry (as much) about infection, because we can generally treat that too.

So a lot of modern medicine seems counterintuitive, because we’re going against our bodies’ natural processes. Which we are, but only because our body doesn’t know we’ve changed the rules.