"Whether it's heat, chemicals, dyes, or styling, it's all doing some degree of damage," Mirmirani says. "A good rule of thumb is, the less you do to your hair, the better."
The good news is today's products, including dyes, are much better suited to our hair than 20 years ago, with technology and research helping to make most styling products actually beneficial to our hair.
How can you undo some of the damage done through countless visits to the salon?
"There are two things you can do," Mirmirani says. "First, cut off the damaged ends and start fresh. And try reducing what you're doing. ... If you notice your hair looking dull and dry, cut back on your styling until you get your hair back."
Larry Baron, the owner and head stylist at Spa Christine in Boston, says the trick to keeping your hair healthy is to maintain its pH balance.
"In order to close the hair cuticle and bring it back to health, you need to keep its pH balance at 4.5 -- that's the level at which your hair will look its best," he tells WebMD. "When it starts to creep up, that's when it starts to look like straw."
Baron's recommendations for maximizing hair health:
- Always put product on your hair before you style with heat. "By putting the product on before you style, you're heating the product, not the hair," Baron tells WebMD.
- Use extensions and cornrows wisely. "If extensions or cornrows are too tight, it can damage your roots by causing too much tension," Baron says. "There's a new technique where you can have extensions glued in and then removed using baby oil, but whatever way you choose, don't overdo it -- hair is strong, but it does have a breaking point."
- Cut your losses. "When your hair is really damaged and dry, amputate," Baron says. "Just cut it off and start over."