Can fright turn hair white overnight?
It’s a common enough belief, with a long history. There are dozens of alleged occurrences over the centuries right up to modern times. Shakespeare even mentions it. But they are all, it seems, mistaken.
It’s not hard to refute. Hair is dead matter, and once each hair emerges from the follicle there really isn’t much the body can do to change it. Sucking the colour out is just impossible. The odd desperate soul has proposed an outlandish scenario where the body could turn existing hair white, but none of these are plausible.
So hair can’t turn white without growing that way. That’s that, then. Not so fast, though. The body may not be able to change the colour of the hairs on your head but it can shed them. And there is a kind of rapid hair loss which, when it strikes, targets pigmented hairs rather than white or grey hairs. If and when the lost hair regrows it comes in without colour, too.
We’re back in the game. A person’s hair can appear to go white, though it’s really just that all their pigmented hairs have fallen out.
But there are still a couple of catches. It doesn’t happen overnight. This kind of hair loss can be very rapid, taking just a few days, but not fast enough to totally restyle a person overnight.
There is also the vexed question of whether a fright, or psychological stress of any kind, can cause hair loss. Those who study hair loss are pretty sure that several factors, including heredity, are needed to trigger it. Stress might be one of those factors.
Alas, most attempts to answer this question have involved asking the victims of hair loss whether there was any stress beforehand to trigger it. Memory is unreliable enough at the best of times, let alone when your hair is falling out, so these studies aren’t that useful. Better designed studies show mixed results. It isn’t yet clear whether stress can cause hair loss.
Fright or not, a person can rapidly go white. It won’t happen overnight, but it will happen.