Your hair follicles have a tiring job, and every once in a while they take a break. At the moment, roughly 90 percent of the hair on your head is growing, while the rest is taking some time off. Some of that hair will resume growing again after a pause of a week or two. A smaller proportion will simply fall out—about 50 hairs a day. But don’t panic, because the same hair follicle will begin creating a new hair in its place. An average hair takes six years of abuse on your head before it drops out and the hair follicle starts over. Eyebrows and eyelashes have a different growing schedule. Eyebrow hairs grow for about 10 weeks, and then rest for the better part of a year. (This is what makes eyebrow shaving such a dastardly revenge tactic.) Eyelash hairs last about three months apiece before falling out and being replaced.
Hair growth is an issue that comes with a boatload of baggage. Hair embarrasses us when it appears in certain places (inside our ears, for example). In other places, it mortifies us when it vanishes. But other than cutting your hair, you have little control over its comings and goings.
Here are some quick facts that can help separate the bare facts from the follicle folklore:
• Hair doesn’t grow faster or thicker after you shave it (on any part of your body).
• Hair doesn’t grow faster at night. Female hair doesn’t grow faster during menstruation. Instead, all hair grows at a constant rate with a brief resting period.
• Frequent washing, blow drying, and dyeing your hair doesn’t destroy hair follicles or slow hair growth. However, these activities might make your current hair more brittle and fragile. But even if you damage a hair to the point of falling out, the same hair follicle will produce a new one to take its place.
• You’re born with all the hair follicles you’ll ever have. As you grow and your skin stretches from infant-sized to adult proportions, your hair follicles simply become more spread out.
• While you’re pregnant, each hair clings on a little bit longer, eventually giving you a fuller head of hair. After you give birth, your body sheds its hair more quickly to make up for lost time.
• The only ways to remove hair permanently are laser hair removal and electrolysis. Both treatments take numerous sessions over the course of many months, and neither treatment works for all people or all hair.
• Wearing hats doesn’t cause hair loss.
Male-pattern baldness, which causes the infamous ring-around-the-baldspot effect, develops gradually and eventually affects about two-thirds of all men. Its causes are genetic, and its treatments are few. A small set of medications give some improvement to some people, but these drugs are often ineffectual. There are only two guaranteed solutions: hair-transplant operations (which are expensive, time-consuming, and may look odd, since hair loss continues around the transplanted patches), and head shaving. If you opt for the latter, you’ll likely tell people that you deliberately chose baldness to emphasize your virile, youthful manliness. Everyone will know the truth, of course, but they’ll also be quietly relieved that you aren’t practicing the dreaded comb-over.
Source of Information : Oreilly - Your Body Missing Manual (08-2009)