If you've ever colored or permed your hair, you know the toll the health of your hair takes. Even if you haven't ever had your hair treated, you might have experienced dry, brittle hair or split ends. Sure you have hair, but as with everything else with your body, just because you have it doesn't mean that it's going to be healthy. If you're going to have healthy hair, you need to take the necessary measures to make sure that you're taking care of it properly.
Sure coloring and treating your hair damages it, but that doesn't mean that in order to have healthy hair you can't ever dye it or treat it. Depending on how you treat your hair (whether that's through coloring it, straightening it yourself or professionally, perming it, and so forth) you have access to different products that fit the needs of your hair. Make sure that you're using the appropriate products for your hair. If you color your hair, make sure that you're using a moisturizing color-safe shampoo and conditioner. Follow the same principle if your hair is permed, straightened, or treated in any other way. Or if your hair is just naturally really dry, make sure that you use a shampoo and conditioner conducive to your hair type.
You should consult with your hair stylist if your hair is particularly damaged. In more severe cases, you might be best off giving your hair a break for a while. All this means is that you should take a break from coloring it (or however else you treat it), minimize your use of blow dryers, curling irons, and straighteners, and work on rebuilding your hair. Your hair stylist also probably has access to more intense forms of repair treatment that will effect results even on the most damaged of hair.
Keep in mind that quality repair products will probably cost a little bit more than what you may be used to buying at the regular store. And depending on the level of damage of your hair, you might even have to specially order repair products. And just because your hair may be in poor condition doesn't mean that it's a lost cause. Hair grows and can work to help repair itself. If you help it along, then your hair can eventually reach a healthy level. And if you become discouraged anytime throughout this process, stop and think about how much better your hair will look and feel once it's no longer dry, brittle, and split. With healthy hair, you'll look healthier and you'll be healthier.