The Premature Graying problem is largely genetic. Hair follicles contain pigment cells that produce melanin, which gives your tresses their color. When your body stops generating melanin, hair presents itself as gray, white, or silver.
It is a growing concern that today even kids as young as ten years old suffer from graying of hair. It was a very rare phenomenon even a few years ago but it is increasing every day. These days, even children are not out of bounds of stress and hence graying of hair starts as early as in a ten year old.