You Love Your: Hair Coloring
But the problem is: Chemicals have to be used to open your hair shaft. Ammonia-free formulas exist, but industry studies have found that they're just as harmful (you have to use more and leave them on longer).
You're in trouble when: After showering, your hair dries almost instantly. That shows just how porous those color chemicals have made it, says Katherine Polite, a colorist at Zanos Salon and Day Spa in Chicago.
Damage-control plan: Many dyes are infused with moisturizers, but to further diminish the risk: Get a pre-color trim (your ends are prone to soaking up excess color); for gray coverage, go semi- or demi-permanent it'll fade faster but is less harsh than a permanent dye (try Clairol Natural Instincts); to highlight at home, avoid pull-through caps, which often result in damaging color overlap (L'Oréal and Clairol make capless kits). Done wrong, major color changes can cause major harm, so leave those to the pros.
You Love Your: Hairbrush
But the problem is: The wrong tool or the wrong technique can tangle or, worse, tear your hair.
You're in trouble when: With your back to a lamp, you look in a mirror and see tiny hairs sticking up along your part and hairline. These aren't "baby hairs" growing in, says Cheri McMaster, senior scientist for Pantene; they're hairs that have broken.
Damage-control plan: Bristles are the key to preventing breakage. They should be soft, smooth avoid those with plastic balls on the ends and spaced out, as on a comb. Don't brush wet hair (it's too fragile) and work in inch-long sections, from ends up to roots.
You Love Your: Heat Styler
But the problem is: Blow-drying, flat-ironing and curling can all cause hair's outer layer the cuticle to lift up, releasing valuable moisture and leaving shafts brittle.
You're in trouble when: You pull out a hair, run your fingernail from root to end (as if curling a ribbon), drop the strand into a glass of water and it doesn't uncurl. Translation: Your hair has lost elasticity, says McMaster.
Damage-control plan: Throw out any heat-styling tool that you've had for more than five years: The older the appliance, the higher the chance that the temperature gauge has gone kaput, says Beverly Hills celebrity stylist Cristophe. Use your blow-dryer's nozzle attachment; it cuts down on cuticle ruffling. Buying a flat iron? Pick one that has ceramic plates: Since ceramic heats up evenly, it straightens hair faster and won't stick to or singe any one spot. (Try Rusk's Ceramic Str8 Iron.) Before ironing or drying your hair, says McMaster, use a spray or serum that contains dimethicone. It will melt in the heat, creating a protective barrier.