Can shock make your hair turn white overnight?

Can shock make your hair turn white overnight?

Shock can make your hair turn white overnight. In 42 years of hairdressing, I've heard of it happening three times. But it has to be a traumatic, obvious shock and I've heard in one particular case the individual literally went to bed one night and woke up with grey hair. I've also heard, almost even worse, that again, through a severe shock, an individual has gone to bed, woken up and seen the hairs on the pillow. All their hair just fell out overnight. But these are traumatic situations which are very rare. As I said, I have only heard of three in my lifetime. Those are the only cases I know of though. Obviously it could be that there are many more.