comprehensive

Fingernails sometimes fall off when they’re damaged — like if they get stuck in a car door.

That has to do with what’s known as the matrix, the spot at the bottom of your nail that’s responsible for growing your nail. Nails themselves are actually little plates of proteins called keratin. All of those proteins are connected, which is what makes one continuous nail.

advertisement

When your finger experiences a shock, like getting stuck in a car door, the matrix temporarily pauses the growth of the fingernail. That pause means the proteins are no longer connected. So the new part of the nail that starts growing isn’t connected to the old part that you could already see — which is why your fingernail falls off.

We investigate the strange science of fingernails in the latest episode of our video series “Boddities.”

Sign up for Morning Rounds

Your daily dose of news in health and medicine.

Related: Watch: Episode 12: What would happen to your eyes if you looked at the solar eclipse?

Related: Watch: Episode 11: Why do bug bites cause bumps on the skin?

Related: Watch: Episode 10: What happens when skin gets sunburned?

Related: Watch: Episode 9: Why can’t teeth heal themselves?

Related: Episode 8: What makes metabolism fast?