Lump Underneath My Betta's Mouth =[

[xamy_valox]

Hi there,
This morning as I fed my fish I noticed my betta ha quite a large lump under his mouth. It looks really red and sore, not sure if it's a growth or if he's hurt himself somehow? I'm gonna try and get a pic but he doesn't like posing so it may be difficult, anyone know what it might be?
It's like where his throat is, where his gill bits split? xx