Tampons absorb to grow thicker and then staunch the bleeding by blocking it. It’s literally called a tamponade.
A vampire walks into a bar. The bartender asks if he’d like some blood. “Just hot water, please,” the vampire responds. The bartender raise an eyebrow, but goes to get the hot water. When he places the mug in front of the vampire, he says, “I thought you were a vampire. Why order hot water?” The vampire pulls a tampon out of his bag and says, “I’m having tea.”
You’re welcome.
They were invented to plug bullet wounds in wartime after all, until nurses noticed they had other practical uses as well.
Don’t quote me on that though, I don’t remember where I read that.
Tampons have been used to manage menstruation for thousands of years. In the 1800s they first started trying to used them for bullet wounds. So they weren’t invented for bullet wounds.
Also, just to be clear, don’t stick a tampon in a bullet wound. They are not at all an effective dressing. In all cases you are far better off just holding a wad of gauze or similar over the wound and applying pressure. A tampon isn’t large enough and doesn’t go deep enough to do any good as packing.