Once you bleach, she explains, you've altered the strength of your hair, making it weaker. If you add blow drying and styling on top of bleaching, you can really damage your 'do, causing hair breakage, a dull look, and split ends.
2. Perms - "Perming refers to either a chemical straightening or a chemical curling," Mirmirani says. "It works by breaking the inner bonds of the hair and re-forming them back together in a different way."
Like bleaching, it weakens your hair, leaving it dull and damaged over time so that instead of luxurious curly locks or shiny straight tresses, your hair looks brittle and dry.
3. Highlights and coloring - Highlights and semi-permanent dyes aren't as damaging as bleach, but they aren't without consequences, Mirmirani says. They can also change the inner structure of the hair, causing a lackluster look and dryness, especially if you frequently color to hide roots or gray hair.
4. Flat iron and blow-drying - "Heat causes temporary changes to the hydrogen bonds that hold hair together," Mirmirani says, and that can make hair look dull.
Over time, the temporary changes can lead to more permanent damage if you tend to blow dry or iron on a daily basis.
5. Ponytails and braids* - "Ponytails and braids can cause hair to break, especially if your style is pulled tightly," Mirmirani says. "If you wear it that way every day, permanent hair damage can occur."
Braiding or putting your hair in a ponytail when it's wet can cause damage sooner because wet hair is more fragile.
6. Over-brushing - Think 100 strokes a day will make your hair shiny and full? Think again.
"Over-brushing your hair can cause split ends and breakage, with the over-brushing causing just too much consistent friction for hair to handle," Mirmirani says.
Cheap brushes don't help either, causing snags and tangles that are hard to get out and resulting in broken hair and split ends.
7. Over-shampooing - "The goal of shampooing is to cleanse the scalp and remove oil buildup on your hair," Mirmirani says.
But over-washing can wash away your hair's natural moisture that helps your hair look healthy, making your hair dry. Although a significant amount of research has gone into making shampoos beneficial for your hair, you can still get too much of a good thing.
"The less vigorous you are in washing your hair, the less damage you'll do to the cuticle," Mirmirani tells WebMD. "And find a frequency to washing your hair that works for you ... whether it's a few times a week or every day."
How do you know when you are overdoing it?
"I have African-American patients who wash their hair once a week to avoid drying it out," Mirmirani says. "You can tell when it's too much if it starts to get dull, which means it's time to scale back on the shampooing."
8. Extensions and weaves* - Extensions and weaves are a lot like ponytails and braids. Over time, they can leave hair broken and brittle. The difference is the damage is at the roots where it is harder to cut out.
"If you have a discomfort or ache in the scalp, that indicates that what you've done to your hair is causing too much pressure at the roots," Mirmirani says.
Worse, traction alopecia is a serious hair loss condition caused by wearing tight hairstyles like extensions for too long a time period. So either keep it loose, or try growing your hair instead of going for instant length.
*If too tight, these styles are damaging. If done correctly, they work as great protective styles.