The back left side of my mouth (gum/tooth) is swollen and i can't eat anything. what could it be?

See a dentist now!: Hi. It sounds as if you have an abscessed tooth. You need to get to a dentist right away! We can't fix that on the internet! Go to your dentist immediately!

Could be...: An infection, a broken tooth, or a wisdom tooth erupting... but these are only guesses since you cannot be accurately diagnosed over the internet. Please see a local dentist for treatment, since you can't eat anything and things can only get worse, really fast.

Dental abscess: A tooth abscess won't go away without treatment and the infection may spread to your jaw, cheeks, sinus and to other areas of your head and neck. A dental abscess is a collection of pus that forms in your teeth or gums as a result of a bacterial infection. Dentist will treat a tooth abscess by draining it and getting rid of the infection. Rec. See your dentist asap.