A strand of hair is an outgrowth of dead cells and the protein keratin that grows up from the hair follicle. Each hair shaft grows about 1/4 inch per month, depending on what stage of growth — active or resting — the hair is in. Genetics determine determine how many hair follicles we have since no new follicles are formed after birth. A woman’s legs and arms contain an average of 13,500 hair follicles.
Ingrown hairs — an annoying consequence of shaving and waxing — occur when a hair curls into the skin and grows in the wrong direction, resulting in a red, irritated bump that can become infected. Though relaxing the muscles during shaving and waxing is said to help prevent ingrown hairs, they can still happen. Some people recommend plucking the hair using sharp-pointed tweezers and then cleaning the area with peroxide; others say it’s best to leave ingrown hairs alone to heal themselves. To help avoid ingrown hairs, rub your skin vigorously with a towel or exfoliating sponge every time you bathe.