Avoid Aspirin When Controlling Swelling
In the immediate aftermath of a sprain, your main objective should be to reduce the swelling. But if you also want to take a pain reliever, aspirin shouldn't be your first-line choice. The reason: aspirin slows the blood's clotting mechanisms and may promote more bleeding into the injured area. For this reason, acetaminophen or ibuprofen are more appropriate pain relievers for new sprains.
And remember that pain relievers don't necessarily help with swelling. For that, you need to rely on the RICE method: Rest, Ice, Compression, Elevation. Of course, if your pain and swelling seem extreme -- or if you believe you may have fractured a bone and not simply sprained the area -- seek medical attention immediately.