What are the causes of premature grey hair?

Is there any relation to thyroid/autoimmune conditions?What are the causes of premature grey hair?
heredity...do not worry just dye itWhat are the causes of premature grey hair?
you can grow gray hair from stress are you having alot of stress and or dying it gray
i know someone who went pure white in one day was caused through a shock
Stress, but it could be hereditary also.
I went Grey at 20, I am convinced it was down to radiation, as at the time I was a classified radiation worker and was burnt out in two consecutive sessions
Old age .
i started getting grey hair at 21...people say i look like George Clooney on acid
and lilac hair die...tried that all over my friends blonde hair when we were about 11 and it was grey for weeks! :-P
Management
Kids!
premature grey hair isn't all that bad, you might go on American Idol and win!
Its genetic.
It's hereditary.
Don't think so, it's a predetermined genetic thing, when your stores of keritin run out.
Stress. I'm currently in my third year at uni, which is proving very stressful. I keep finding grey hairs and I'm only 22. I put it down to stress because the bottom half of the strand is blondey/brown and the top half is silvery/blonde, which would tie in with the growth of my hair since September, which is when I started uni!





SCARY!!
Old man attitude.
stress. grey hair dye