Well, between your joints, you have something called synovial fluid, which is basically there to keep you nice and lubricated, honey.

But every time you crack your knuckles, you're essentially pulling the bones away from each other.

And as a result, the space between them gets bigger.

And so the synovial fluid, which is the same amount of fluid, has to go into a low pressure zone.

And so any gas in it gets pulled out, forms a bubble and pops.

And that is the noise that you're hearing now.

Is it bad for you?

Most research has found that it doesn't cause things like arthritis.

It probably isn't bad for you, though Some studies have shown that it decreases grip strength over time.

But the biggest risk seems to be that the more you do it, the more you annoy everyone around you.