What is hair, exactly? This part answers all your burning questions about hair: what it’s made of,
how it grows, and how you should take care of it so that it will last a lifetime — or at least as long your genetic makeup allows it to hang around.
Hair 101: What exactly is hair?
Most people have no idea what really lurks beneath their hair,unless they’ve been shaving it off already.
For something that you play with, obsess over, color, cut, and twist into odd shapes, hair is surprisingly dead. Yes, the hair you think looks so vibrant and alive is actually not alive at all. I’m not saying that you should ignore or mistreat your hair. For something that’s dead, hair is quite capable of responding to good treatment or bad.
Hair is technically part of your skin, although like fingernails and toenails, it grows and separates from your skin. The average head contains around 100,000 hair follicles, and your entire body is
home to around 5 million hair follicles. Most of the complex activity that keeps your hair growing goes on below the surface.
The active growth phase of a hair follicle, called the anagen phase, averages around three years. At any given time, about 90 percent of your hair is in the anagen phase, and the other 10 percent is taking a rest in the telogen phase, which is the resting phase, and
disappears from your head.
Hair grows about 1⁄2 inch a month (although it certainly seems like more when you need a haircut!) and grows to a length of 11⁄2 to 3 feet before growth stops and the hair falls out. (In a coming post, we tell you all you ever wanted to know about hair, right down to its
roots.)
The many possible causes of hair loss
Everyone loses around 100 hairs from their head every day, but serious hair loss isn’t a “one cause fits all” type of problem; many factors contribute to hair loss, and we give you the full rundown in another coming post. The most common causes of hair loss are listed here.
Genetics: Yes, you knew it all along: It’s Mom’s (or Dad’s) fault that you have no hair. The overwhelming majority (up to 98 percent) of men with balding fall into the genetic category.
Female genetic balding occurs much less frequently, but up to 50 percent of women have hair loss related to their inherited genes. (See Chapter 4 for more on genetics and hair loss.)
The good news is that only seven percent of men develop the most advanced balding pattern (left with just a 3 inch wreath of hair around the side and back of the head). If you’ve inherited this pattern, it’s usually evident by the time you’re 30.Genetic hair loss in men generally falls into one of several distinct hair loss patterns identified under the Norwood classification system . In balding men, the hair around the sides of the head almost always retains a normal,thick appearance. In women, genetic hair loss is different; for one thing, it tends to occur as overall hair thinning (including the sides of the head) rather than loss of hair on certain areas
of the head.
Diseases: A number of diseases as well as hormonal influences, including thyroid disease and anemia, cause hair loss.Autoimmune disease also can cause patchy hair loss.
Mechanical causes: Mechanical hair loss is caused by external forces such as tight braiding, rubber banding, turbans, or other hair torture devices that put stress and strain on your hair.
Stress: In some cases, stress can contribute to hair loss in those who are genetically predisposed to it or can result in a sudden loss of hair in a condition called telogen effluvium.
Medications: Many medicines, most notably anabolic steroids, birth control pills, antidepressants, and tranquilizers, can cause hair loss.
Female genetic balding occurs much less frequently, but up to 50 percent of women have hair loss related to their inherited genes. (See Chapter 4 for more on genetics and hair loss.)
The good news is that only seven percent of men develop the most advanced balding pattern (left with just a 3 inch wreath of hair around the side and back of the head). If you’ve inherited this pattern, it’s usually evident by the time you’re 30.Genetic hair loss in men generally falls into one of several distinct hair loss patterns identified under the Norwood classification system . In balding men, the hair around the sides of the head almost always retains a normal,thick appearance. In women, genetic hair loss is different; for one thing, it tends to occur as overall hair thinning (including the sides of the head) rather than loss of hair on certain areas
of the head.
Diseases: A number of diseases as well as hormonal influences, including thyroid disease and anemia, cause hair loss.Autoimmune disease also can cause patchy hair loss.
Mechanical causes: Mechanical hair loss is caused by external forces such as tight braiding, rubber banding, turbans, or other hair torture devices that put stress and strain on your hair.
Stress: In some cases, stress can contribute to hair loss in those who are genetically predisposed to it or can result in a sudden loss of hair in a condition called telogen effluvium.
Medications: Many medicines, most notably anabolic steroids, birth control pills, antidepressants, and tranquilizers, can cause hair loss.
