8 Ways You're Damaging Your Hair

Kristin LaVerghetta, 23, from Norton, Mass., has hair to die for. It's shiny, it's full, it has just the right amount of bounce, and worse yet, she makes it all look completely effortless.

What's her secret when it comes to having great hair, other than good genetics?

"I don't color it -- never have," LaVerghetta says. "I blow dry it every day and use a straightener sometimes, and I shampoo and condition every day, which works best for my hair type."

To protect her hair against the heat of the blow dryer, she uses hair product first. Her secret to hair success: Less is more.

Most of us aren't as kind to our tresses. From highlights to lowlights, chemical perms to chemical straightening, blow drying, braiding, and bleaching, how we treat our hair has a direct impact on how healthy -- or unhealthy -- it looks.

Causing split ends, lack of luster, or hair breakage, our styling habits play havoc on the one thing we're trying to capture -- beauty. Hair experts explain the anatomy of the tresses on our head, offer insight into the damage too much styling can cause, and give advice on how to keep your locks looking luxurious.

The Anatomy of Hair

"Hair is fiber, much like wool," says Paradi Mirmirani, MD, a staff dermatologist at the Permanente Medical Group in Vallejo, Calif. "It's bundled together tightly in the middle and protected on the outside by a cuticle."

Every hair has three layers -- the inner fibers make up the medulla; the cortex surrounds the medulla; and the cuticle is the outer layer that protects the inner, more sensitive components from damage, Mirmirani says.

Each hair grows about 1/4 inch every month out of a follicle on your head, and it can keep growing for up to six years. Then as part of the natural cycle of hair, it will fall out and make way for a new hair.

How long your hair is depends on how long your growing cycle lasts. If it's only two years instead of six, your hair will naturally peak at a shorter length. The same goes for the thickness of your hair: Thick hair grows out of large follicles; smaller, narrower follicles produce thinner hair.

Worse, for men and women alike, a person goes bald if the hair follicles that produce a new hair shrink in size or become inactive.

The circle of life for a hair, however, depends on a lot of things, and styling is one of them: The more you style, the more you change the natural makeup of your hair. And although the amount and intensity of styling a person's hair can take depends on genetics, the texture of your hair, and its coarseness, less is always more when it comes to hair health.

"If the cuticle of a hair is damaged as a result of overstyling, the inner core is exposed, causing dryness, a lack of luster, and static," Mirmirani says.

Basically, your quest for beauty backfires.