It is not true that fingernails, toenails, or hair continue to grow
after death. Nails and hair may appear to be longer because of the
desiccation of the surrounding flesh, but actual growth has not
"We dehydrate after dying. Our flesh dries and, in so doing, pulls
away from nails and hair. Thus, though the nail on our big toe, for
example, remains the same length as before, the toe it is seated upon
shrinks. Because we are accustomed to nails and hair growing, not
hands, feet, and heads shrinking, we perceive this change as an
increase in one rather than a decline in the other.
To quote the respected forensic anthropologist William R. Maples:
It is a myth that fingernails and hair continue to grow after death.
What really happens is that the skin may retract around them, making
the hair and nails prickle up and jut out more prominently. Erich
Maria Remarque, in his novel All Quiet on the Western Front, imagines
a dead friend's nails growing in weird, subterranean corkscrews after
his burial. It is a powerful, disturbing image, but it is pure
moonshine. No such thing occurs."
Snopes Urban Legends Reference Pages: Coffin Nails
"The skin around the hair and fingernails will desiccate (i.e., lose
water) and thereby shrink. When the skin shrinks, it retracts, making
hair and fingernails look longer, as if they'd grown.
Think of it this way: a fifty foot tree grows in ten feet of swamp
water. The visible part of the tree is 40' tall. A few months later, a
drought causes the water level to drop five feet. Now the visible part
of the tree is 45' tall. Did the tree grow in a drought? No, but you
can see why people would think it did."
The Straight Dope: Do hair and nails continue to grow after death?
"Many people believe that a person's hair, fingernails and toenails
continue to grow after death. Despite what you may have read or seen
in the movies, this is false. Once a person has died all growth of the
hair and nails ceases. After death the body dehydrates and the skin
around the hair and nails will recede a little making it appear as the
deceased's nails and hair have grown. However, it is only an optical
illusion. The nails and hair remains the same length as before but
more of it is exposed due to tissue shrinkage."
About Dying: Do Hair and Nails Continue to Grow After Death?
My search strategy began with visits to The Straight Dope and Snopes,
two of the Web's very best sites for separating fact from myth. I also
used this Google search string:
Google Web Search: "fingernails and hair continue"
I hope this is helpful. If anything is unclear or incomplete, please
request clarification; I'll gladly offer further assistance with this
question before you rate my answer.