Page 55 - Cosmetology

An older Hmong man with gray hair

Aging

Older people tend to develop grey hair because the pigment in the hair is lost and the hair
becomes colourless. Grey hair is considered to be a characteristic of normal aging. The
age at which this occurs varies from person to person, but in general nearly everyone 75

years or older has grey hair, and in general men tend to become grey at younger ages than
women.

It should be noted however, that grey hair in itself is not actually grey - the grey head of
hair is a result of the contrast between the dark and white/colorless hair forming an
overall 'grey' appearance to the observer. As such, people starting out with very pale

blond hair usually develop white hair instead of grey hair when aging. Red hair usually
doesn't turn grey with age; rather it becomes a sandy color and afterward turns white. In
fact, the gray or white appearance of individual hair fibers is a result of light scattering
from air bubbles in the central medula of the hair fiber. Some degree of scalp hair loss or

thinning generally accompanies aging in both males and females, and it's estimated that
half of all men are affected by male pattern baldness by the time they are 50. The
tendency toward baldness is a trait shared by a number of other primate species, and is
thought to have evolutionary roots.

It is commonly claimed that hair and nails will continue growing for several days after

death. This is a myth; the appearance of growth is actually caused by the retraction of
skin as the surrounding tissue dehydrates, making nails and hair more prominent.

Pathological impacts on hair