Ondrea Barbe(Magazine)

What's Your Damage?

Check the Bulb
Pluck out a strand of hair at the root and examine the base. Strong hair has a thick bulb. “If there’s no bulb, the hair follicle isn’t healthy,” says Michael Shaun Corby, global creative director for Alterna Hair Care. The cause? Damage from styling or, potentially, genetically linked hair loss.

Give It a Tug
Wrap a strand of hair around your index finger and thumb (like a piece of string), then use your other hand to tug on it. If it snaps immediately, your hair is lacking moisture; if it stretches “like bubble gum,” says Corby, it needs protein, which strengthens the hair’s keratin bonds.

Do the "Sink or Float" Test
Drop a strand of hair into a glass of water. A healthy strand will float. If it sinks, the shaft is porous. This can happen to color-treated hair, but it can also occur with a protein deficiency.

To get a fair picture of your hair’s overall health, repeat tests on at least four strands from different parts of your head, suggests Donna Maggi, education manager of Nioxin, a hair- and scalp-care company.

Stop a Bad-Hair Day Before It Starts

If you go outside with wet hair

Outdoor elements (wind, cool temperatures) can be rough even for dry hair, explains Corby. But when hair is wet, it’s actually more fragile and susceptible to breakage.

Healthy-hair fix: Try styling products designed to cut drying time. The Paul Mitchell Express Style line, for example, is formulated with technology to help hair dry faster.

If you use a subpar blow-dryer

In a cheaply made blow-dryer, the coil and motor can overheat, frying your hair’s cuticle. The tip-off: “The louder the sound, the poorer the quality,” Corby says. But a professional blow-dryer isn't always better, says Erin Anderson, VO5 celebrity stylist. “They’re powerful and can burn hair if used incorrectly,” she says.

Healthy-hair fix: an ionic blow-dryer. Ionic technology shrinks water molecules, so hair dries faster but with less damage. Try the T3 line (the Rolls-Royce of dryers), or you can find one for less, like Conair ION Shine 1875 Watt Dryer, $37.

If you still smoke

That nasty habit is not only bad for skin — “it pollutes your hair,” says Anderson. Smoke leaves residue on the scalp and hair, making it look dull.

Healthy-hair fix: Um, quit. Also, use a clarifying shampoo monthly, and consider a “facial” for your scalp. “Just like the rest of our skin, the skin on our scalp needs to be addressed,” says Maggi. Try Nioxin Scalp Renew, an in-salon dermabrasion treatment that removes buildup and unclogs follicles.