Hair Loss and Aging
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 aging and baldness is a trait shared by a number of other primate species, and is thought to have evolutionary roots.
Older people tend to develop gray hair because the pigment in the hair is lost and the hair becomes colorless. Gray 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 gray hair, and in general men tend to become gray at younger ages than women. 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; red hair usually turns a sandy color and then turns white after that.