Have you ever walked across a cemetery and thought about the growing, curling fingernails of the corpses beneath? This disturbing idea is probably the kind of thing you heard around a campfire as a kid. It has such a morbid appeal that artists have used this image in books and movies for a long time. Johnny Carson even joked, “For three days after death, hair and fingernails continue to grow, but phone calls taper off.” Despite the popularity of this idea, it’s just not true. To quote the expert opinion of forensic anthropologist William R. Maples, “It is a powerful, disturbing image, but it is pure moonshine. No such thing occurs.”
This myth does have some basis in reality. After you die, your body dries out or becomes dehydrated. As the skin dries out, it shrinks (this is a different kind of shrinkage than what happens to a man in cold water). The shrinking or retracting of the skin around the hair and nails makes them look longer or more prominent compared to the shrunken skin. It’s just an optical illusion, though; the nails and hair haven’t actually grown at all. In order to keep growing, hair and nails require a complex mixture of hormones that are just not available to the body after death. Studies of the cellular regulation of hair growth confirm that a person would need to be alive for their hair to keep growing. There’s no need to book a haircut and manicure for your corpse—no matter how long it’s been since the last one.