Plenty of money is spent each year by men and women who are trying to preserve their youth by covering up those tell-tale patches and streaks of hair that are turning gray. Graying hair may be nothing more than a sign of aging, but it may also be an indication of a medical condition that requires treatment. If in doubt, be sure to consult your doctor.
The best known cause of graying hair is simply getting older. MedlinePlus, a service of the U.S. Library of Medicine and the National Institutes of Health, explains that hair color is determined by a pigment, known as melanin, that's produced by the hair follicles. As we age, the follicles produce less of this pigment. The first gray spots will probably appear at the temples and eventually extend across the top of the head. Medline Plus notes that graying often begins in the 30s, and is genetically determined. For instance, Asians tend to gray at a later age than Caucasians.
Some people start turning gray well before their middle years. In fact, premature graying can occur as early as childhood. According to the Mayo Clinic, most children who go gray are healthy, but their hair pigment cells simply stop making pigment. Premature graying can be associated with other conditions, so it is best to check with your doctor to determine if the gray hair can be traced to a medical reason such as vitiligo, alopecia areata, a thyroid disorder, anemia, or vitamin B-12 deficiency. The Mayo Clinic notes that the treatment of gray hair is the same at any age. It can be covered with hair dye, or you can minimize the look with hair styling techniques.
A patch of gray hair or a white streak is called poliosis, and it can occur in children as well as adults. The Mayo Clinic explains that some babies are born without pigment cells in a patch of hair follicles. Other times, the immune system can accidentally destroy pigment cells in an area. Poliosis can be inherited. It also may be associated with skin disorders, such as vitiligo, and genetic disorders, such as Marfan's syndrome and Waardenburg's syndrome, according to the Mayo Clinic.
You may have heard ghost stories or old wives' tales about someone turning gray overnight from a bad scare, or some other psychological shock or trauma, but that's not the case. Hair that has already grown out won't spontaneously change color, but a type of baldness known as alopecia areata may have contributed to the tall tale. Disabled World Disability and Health News reports that thicker, darker hairs may stop growing and fall out before gray hairs, and that can make it seem the gray hair appeared more suddenly than it actually did.