system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: why do we try to reduce the swelling in the ankle/wrist after an accident? Surely our bodies evolved to swell up as it is somewhat beneficial after an injury, so why do we think it better to try to stop it/reduce it?

I know why we need to stop head injuries from swelling up, don't start explaining about pressure damaging the brain.
gpt
Looks like nobody got it yet so I'll answer. Swelling is a natural splint. Back in our hunter gatherer days, when we hurt ourselves, there were no time outs. You kept going or you died. If you've partially torn some of your ankle ligaments, you still may need to walk or even run on it. The swelling immobilized the joint to reduce the risk of further damage. May have taken a long time to heal, but at least you kept up with the rest of the clan.

Now we try to reduce swelling. Why? Because the fluid around the joint is relatively stagnant and deoxygenated. Not the best environment for tissue healing. This is why we ice, to reduce swelling so fresh blood can get to the injury and start the healing process. But what about that nice natural splint, you ask? Well now you don't have one, so stop hobbling around on it and put it up on the coffee table, ferchrissakes!