When our bodies are functioning well, cells in our hair follicles called melanocytes generate pigments -- the chief one being melanin. When the melanocytes stop producing these pigments, we sprout a transparent hair, which appears as an unsightly gray due to the color of the dead cells that comprise the strand.
Why does this happen? The most common reason is heredity; premature gray hair is yet another thing we can blame on our parents. But there are also several medical conditions characterized by graying of the hair. A B-12 deficiency, a thyroid imbalance, and anemia can all cause premature gray hair. And if you needed yet another reason to quit smoking, there is new evidence that smokers are four times more likely to go gray at a young age.
answered by S S