As people age, hair follicles stop producing melanin, the substance that creates hair color. Gray hair has low levels of melanin, while white hair has none.

Hairs don’t actually turn gray. They grow out that way from the scalp, becoming more visible as darker hairs around them fall out.

The decrease in melanin makes hair drier and coarser. As a result, gray hair is especially resistant to dyes, permanents and other treatments.

A stress, illness or severe weight loss causes the older, darker hair to fall out, exposing the gray hair.

A B-12 deficiency, a thyroid imbalance, and anemia can all cause premature gray hair.

The smokers are four times more likely to go gray at a young age.
Age is probably the main factor, although many people get gray hair as early as their teens. The average age for graying to begin is 30 for men, 35 for women.
Genetics play a role; often, early graying runs in families. Race is a factor as well, with white people tending to go gray earlier and faster than those of other races.

Popularity: 20% [?]