What causes gray or white hair?

Question

I have a patch of white hairs all growing together just behind my left ear. What causes this?

Answer 1

I think the asker wants an answer better than just old age...That's a great question.  Why does hair stop showing the pigment in old age or any other time?

Answer 2

You may have inadvertently touched some chemical with effects on your melanocytes.

Another reason could be a lack of some nutrients (mainly vitamines of the B group)  due to anemia or to a too poor diet diet (it happens in almost anorexic girls, or in vegan that are not cautious about their vitamine intake).



Usually genetic reasons are accepted only for whitening that happens after 20-25 years of age.

An earlier whitening, accidents apart, is really rare and  can have several different causes.

One is the intoxication or poisoning of melanocytes.

Medicines toxic for the hairs melanocytes are , for instance , chlorochin/ chloroquine and over dosage of zinc. There could be metabolic  reasons like phenylketonuria or homocystinuria ( Cystathionine beta synthase deficiency).

It seems possible also that a very high fever or a sudden shock may destroy some melanocytes or have an influence on their cycle.

It can also accompany a set of quite rare illnesses (it will be absurd to list all) or be linked to local alopecia or vitiligo

The easiest answer is you might have touched some chemical without knowing it, and that area of your scalp/hairs immediately after

Answer 3

stress and old age.

heredity too i think

Answer 4

Old age. Maybe for generations in your family may have gray hair but is young not old...