Hot temps, flat irons, ripping through your strands at warp speed with the wrong brush—you probably are aware of a whole bunch of things you should NOT be doing in your quest for healthy hair and an equally healthy scalp . Unfortunately, there's a whole other list of things you probably had no clue were contributing to the damage.


Stress
So we had this trigger covered in the skin department…turns out it’s also not so great for strands. “Though high stress levels and a poor diet are generally associated with breakouts and other skin issues, they have a huge impact on hair texture and growth,” explains Ilias Zarbalis, master stylist and owner of Ilias Zarbalis in New York. One area of the head stress really hits hard: your scalp. “You may find your scalp becomes oilier and also breaks out when you are stressed,” says Anabel Kingsley, associate of the Institute of Trichologists and the daughter of “hair guru” Philip Kingsley. “This is because stress, through a convoluted route, can raise levels of testosterone, which in turn can affect skin secretions. In those that are predisposed to dandruff , stress can also trigger flareups of flakes and itching.”

Hot Showers
Different types of water can leave hair coarse and dry, leading to breakage. Zarbalis recommends always using a deep-conditioning treatment after swimming in a chlorinated pool or salt water, and keep super hot showers to a minimum.

Oils
It isn’t uncommon for people to rub oils onto their scalp to clear dandruff. “However, as dandruff is usually oily and not dry, this simply makes flakes stickier. Rubbing in oils can also irritate the scalp,” Kingsley says.

You May Also Like: The New Way to Wash That Will Totally Change Your Hair

A Too-Tight Ponytail
Wearing hair back too tightly can cause a type of hair loss known as traction alopecia. “The traction placed on the scalp and hair follicle can break hairs, pull them out and eventually, if done for an extended period of time, permanently damages the hair follicle and leads to permanent hair loss,” Kingsley explains. As a general rule, if your hairstyle is making your scalp sore, it is likely damaging.

Scratching Pimples
This no-no sounds a little gross, but if you find a pimple on your scalp , apply a soothing scalp toner and try your best leave it alone (as in, don’t touch it!). Kingsley says good ingredients to look for are camphor (it’s soothing and cooling) and witch hazel (an astringent). “Picking and scratching pimples on your scalp can actually cause small scars to form and may even lead to secondary infection.”

Cheese and Champagne
Stop everything and regroup. “We are not entirely sure why champagne, white wine and cheese are common triggers of dandruff, but from our many years of experience we have definitely seen a strong connection,” Kingsley says. “One theory is that champagne and white wine can disrupt blood sugar and the balance of yeast on the scalp.” (Dandruff is thought to be caused by an overgrowth of the yeast, malassezia furfur.) “In terms of cheese, it is very hard to digest. It is thought that this may trigger an inflammatory response in certain individuals.” But, rest assured, she does say trigger foods are not the same for everyone. “Other common offenders are spicy and sugary foods.”

The Wrong Brush
It’s important to be gentle with any brush you use, but consider this: Metal-pronged brushes can also scratch the scalp—and if they become very hot when under a blow-dryer, they may actually burn the hair and scalp. “Boar, nylon and rubber bristles have a softer touch and are less irritating to the scalp because of their give,” says Tim Wandrey, national director of education and style at The Red Door by Elizabeth Arden.

You May Also Like: 9 Must-Have Products for Super Straight Hair

Alcohol and Fragrances
Shampoo and styling products can be big-time scalp irritants, as they can contain alcohol and fragrances that can react poorly with your own body chemistry. “If you are sensitive to certain shampoos, try switching brands or use a medicated dandruff shampoo that can soothe your scalp,” says Ben Stewart, national creative director at The Red Door by Elizabeth Arden.

Overuse of Dry Shampoo
Bad news for second-day (and third and fourth) hair: Too much dry shampoo can build up on the scalp and cause itching, flakiness. “It can also create dullness, and if it builds up excessively on bleached or compromised hair, it can ruin the elasticity and cause breakage,” Stewart says.