When I was about 8 or 9, I ran face first into a dumpster and chipped my two front teeth. I had to have a couple of root canals as a result. One of them developed an abscess 5 years later and caused my face to swell up like a balloon. I was hospitalized for a week and had to have two surgeries to fix it.
If you think you may have an abscess you should definitely get that checked out. sometimes they'll clear up on their own, but other times they go bad and can have complications. I was told when I had mine that it could have killed me, but mine was not minor, it was quite bad.