Hamster infection

Question
My pet Chinese hamster has this really swollen, like popped out area right next to his nose. I was wondering what it might be and that you can possible tell me a cure of it.
He has also gained considerately heavy if that has something to do with the swelling.

Thanks,Jordan

Answer
It may be a tumour, an abscess, a cyst or even a wart.  The best way to find out what it is and what to do about it is to take him to the vet.  The weight gain could be related if it's a tumour and it's caused by cancer spreading, however it could also just be because he eats a lot or doesn't exercise enough.