Do hair and nails grow after death?
From Wigipedia, the free hair encyclopedia
It is one of the most durable bits of graveyard folklore: that after a person dies, their hair keeps growing and their fingernails keep lengthening, as though the body has not quite gotten the memo. It is a wonderfully creepy idea. It is also wrong.[citation needed]
Why it cannot be true
Growing hair and nails is hard, unglamorous metabolic work. It requires living cells in the hair follicle and nail matrix dividing over and over, and that division needs a steady delivery of glucose and oxygen carried by circulating blood. When the heart stops, the deliveries stop. Within hours the cellular machinery shuts down for good. No fuel, no division, no growth.
So the honest encyclopedia answer is: no. A corpse’s hair is exactly as long tomorrow as it is today, give or take the occasional strand falling out.
Why it absolutely looks true
The illusion is real even if the growth is not. After death the body begins to lose water, and skin and soft tissue dehydrate and retract. Hair shafts and nails are made of keratin — already dead, already dry — so they barely shrink at all. The skin around them, however, pulls back.
The nail bed recedes from the base of the nail, exposing pale keratin that used to sit below the skin line and making the nail look longer. On the face, retracting skin can reveal the roots of stubble, producing the unsettling “five o’clock shadow” sometimes noted on the recently deceased. The measuring tape would disagree, but the eye is convinced.[citation needed]
A myth with good PR
Part of why the belief survives is that it has a famous literary champion. In Erich Maria Remarque’s 1929 novel All Quiet on the Western Front, the narrator broods over a dead comrade and imagines his fingernails growing on after burial in slow, “subterranean corkscrews.” It is a haunting image. It is also, biologically speaking, pure moonshine.
The story spreads easily because almost no one runs the experiment, and because it sounds plausible — we know hair and nails grow, and a few days is exactly long enough for the skin to do its quiet retracting. The myth is, in a sense, a tiny triumph of dehydration over arithmetic.