My grandfather had it once, and so did a guy in my class. (They're fine, though. )

Anyway, good luck with the surgery. If you need one, that is.

How will I know if I need it? I guess I should get it checked out.

What you have sounds like an incarcerated hernia. If you're in a lot of pain, you can be certain that's what it is. Make sure you get it precisely diagnosed and operated upon as soon as you can. Don't mess with it, or apply extreme pressure to it any more. It may rupture if you do that, and that may very likely kill you. If it isn't treated soon, it'll quite likely do that itself.

Don't panic, you'll live through it, given it's taken care of in the next day or so. Make sure you don't do any physical labour, work, or do anything that may strain it in any way.

I'm pretty sure that's what you have, due to a family member of mine being diagnosed with the same thing earlier this year, and having it treated a day later. That's how I know this.

Just stay calm, and don't strain yourself. Thousands of people have had this before, and lived through it. Yes, they needed surgery, but you'll live through the operation. Hardly anyone has died from a hernia being treated.

-Ngakunui

Ouch. That's most likely what that is, so yes, definitely get that checked out ASAP. But don't worry yourself to death. It's extremely common, and you're not about to die or anything like that.

And my understanding is that it's a comparatively minor surgery. But still, surgery is extremely annoying...

@Ngakunui: No, it's not painful. I won't touch it anymore, though. I'll have to wait a few hours for my parents to get home.

@ToM Dracone: Not so worried anymore. Dad had his for a while before he had it fixed. But I'll still get it checked out as soon as I can. What a bother though, this while likely mean I have to stop Thai Boxing for a couple of weeks...