What is hair?

Every hair is a bundle of protein called keratin that grows up out of a structure called the hair follicle. Hair follicles cover all of your skin, except on the palms of your hands and soles of your feet.

Humans have two types of hair: Vellus hairs are the soft, fine, "peach fuzz" hairs you may see on your face, stomach and back if you're a woman. Terminal hair is long, coarse, and dark, and grows in the scalp, pubic and armpit areas in both men and women.

Hair is a non-living body structure composed primarily of a protein called keratin that is produced by organs within the skin called hair follicles. The human body has roughly 5,000,000 hair follicles, about 100,000 of which are within the skin of the scalp. This number remains relatively constant from birth through young adulthood and decreases afterward with advancing age.