It's an old gross-out story usually shared at slumber parties or around campfires: Once you die, your hair and nails continue to grow. Theoretically, if you opened up, say, Mozart's tomb, he'd have fingernails that rival a RuPaul's Drag Race contestant and hair as long as J. Lo's. It's a common theory that many people believe, but what actually happens to your hair and nails after you die? Is there any truth to the old wives' tale?
As it turns out, no. According to science, your hair and nails stop growing once you die, and that's just how the cookie crumbles. Hair and nail growth requires the production of new cells, which is impossible after death. Energy in the form of glucose is required for many cellular processes, including the growth of hair and nails. Glucose creates energy when it is burned off with oxygen. The heart pumps oxygen through the body using blood as its mode of transportation. So when your heart stops beating, oxygen can't burn glucose, glucose can't be used to create new cells, and nothing in your body will continue to grow.
While it's true that certain cells do take longer to die than others, it doesn't seem likely that in the "three to seven minutes" it takes for a nerve cell to die you'll get any kind of sufficient hair and nail growth. But where does the myth come from?
Of course, as with many old wives' tales, this myth does have some basis in fact. While our hair and nails do not actually get longer when we die, they do appear longer. Over time, a dead body will become dehydrated. This causes one's skin to shrivel and retract. Dried up skin could possibly give the illusion that hair and nails had become longer over time. It's likely this appearance is what started the myth to begin with.
Though this myth is officially busted, I'd admittedly enjoy an episode of The Walking Dead with a horde of zombies and their 20-foot-long fingernails. That'd be hilarious.