8 Reasons You Have Dandruff & How To Prevent It

Itching doesn't make it go away.

woman with dandruff on scalp Zyn Chakrapong / Shutterstock

It's deeply unpleasant to wake up expecting things to go your way and then to discover that you've got a walloping case of dandruff.

But guess what? Dandruff is a common skin condition, affecting approximately 50% of the population. And while it's a bit itchy and embarrassing, it's usually absolutely treatable.

But to treat dandruff, it's important to understand what causes it.

What causes dandruff?

Dandruff itself is actually a reaction wherein the body produces too many skin cells, which gather on the scalp and fall off in white flakes onto shoulders.


There are lots of different things that can cause this drying of the scalp, but there's one thing that we can all agree on: no matter what causes it, getting a case of dandruff isn't just painful, uncomfortable and gross, it's also totally annoying in every shape and form.

RELATED: 21 Best Dry, Itchy Scalp Remedies That Actually Work


While there are dozens of different things that can cause dandruff, there are some common things that kick it into high gear. Keep them in mind when entering the colder months of the year when you're way more likely to expose your scalp to colder climates that it can handle.

Taking care of your hair starts with taking care of your scalp. Start treating it well and it will respond in kind.

It's also worth mentioning that it isn't just having dry skin that causes dandruff. Having an unhealthy scalp also causes dandruff. If your scalp gets too dry, it's not producing enough oil, and if your scalp is too oily, it overproduces oil, both of which can trigger dandruff.

Here are 8 common causes of dandruff.

1. Allergies

You know how sometimes you'll buy a new tube of mascara and find your eyes watering all day? Or maybe you get a new lotion and your arms and legs break out in hives?


When this happens, it's usually because we have an allergy to the product that we have purchased.

This can be true for all things that touch the scalp, too. You might think that new finishing spray is the bee's knees, but it could be that your scalp doesn't. Try changing out your products if you suspect they may be to blame for your latest case of dandruff.

2. Skin conditions

If you know that you have a skin condition like eczema (also known as seborrheic dermatitis) or psoriasis, you may find that you get also dandruff as a result of oily, irritated skin. Contact dermatitis and fungal infections called malassezia can also cause dandruff.

This kind of flaking is just your skin condition manifesting itself on another part of your body. To treat it, speak with your dermatologist about your different options.


A word of warning: the scalp and the hair are different from other areas of your body, like your face. As such, slapping a cream designed for your cheeks onto your scalp without a doctor's say-so could end in a veritable disaster.

3. Certain shampoos and styling products

Similar to allergies, there are certain hair care products or over the counter shampoos that may cause irritation to the scalp. It's also important to note that the frequency in which you wash your hair affects your scalp; not shampooing enough creates oil build-up, while shampooing too much removes natural oils.

If you find that your scalp has a sensitivity to the products you use, ask your doctor about switching to a medicated shampoo. Ingredients like zinc, selenium sulfide, and ketoconazole found in these medicated shampoos treat dandruff.

RELATED: Why Is My Hair Falling Out? 9 Triggers Of Hair Loss In Women (And What To Do About It)


4. Stress

Guess what's not good for your entire body? Stress.

All you need to go is a cursory Google and you'll quickly find that many prominent scientists, researchers, and doctors have concluded that when you get actively stressed out, it actually causes a gigantic change in your physical makeup.

That's right: when you're stressed, you're chemically a different person than you normally are.

One of the shifts that happen when a body is experiencing stress is that the scalp is negatively influenced. Sudden changes in the health of your scalp can lead to hair loss. So, stress is something we should all make a concerted effort to fight in order to stay happy and healthy.


5. Overstyling

You just want to look awesome every day, but if you're a person who co-sleeps with their blow dryer and you've noticed that you've got more of the white storm happening on your scalp , your blow dryer may be to blame.

Blow dryers are great at drying out your tresses, but they are also great at drying out your scalp. A dried out scalp is an unhealthy and flaky one riddled with dandruff. It's also hard to bounce back once you've got it, because using a blow dryer makes your dandruff worse.

Give your hair a break between blow drying if you suspect this is where your case of dandruff came from.

Curlers, curling irons, and even straighteners (anything that adds heat to your scalp) is going to run the risk of drying out your scalp when used daily. If you absolutely must, make sure you're giving your scalp some good loving on your off days. Try a fancy hot oil treatment, for example.


6. Diet

Though studies haven't yet proven that your diet could contribute to the presence of dandruff, some experts suggest certain dietary changes. If your diet can affect your skin, brain, mood, energy, and mental health, it's logical to think that it may also affect your scalp.

Experts and doctors recommend cutting out or limiting sugar intake, as well as limiting beer or wine. Add fruits and vegetables, healthy fats, B vitamins and zinc.

7. Unbrushed hair

Not all hair types require the same amount of brushing. But for the most part, every single hair type does require brushing or combing out throughout the week or month.

What happens when you don't brush your hair often enough? You can develop a case of dandruff.


Dandruff can collect and thrive around your hair's cuticles. If you aren't evenly distributing the oils in your hair with brushing, you aren't just inviting tangles, you're inviting your dead skin flakes to collect on top of your scalp, leading to blockages, which can lead to unhealthy hair, which can lead to dandruff.

8. Other factors

Along with skin or scalp conditions, allergies, and stress, there are other contributing factors to dandruff: your sex and hormones, age, neurological conditions, and weakened immune system can also cause dandruff.

According to a 2015 review, the prevalence of dandruff peaks around age 20 but decreases after age 50. Men are also more likely to have dandruff, as androgen hormones like testosterone stimulate the sebaceous glands, which create oil.

Individuals with ailments like HIV, pancreatitis and hepatitis C are more likely to suffer from dandruff, with 30-80% of people with HIV reporting having eczema.


RELATED: Why Your Hair Hurts When You Take It Out Of A Ponytail

How to Prevent Dandruff

Though dandruff is irritating — literally — there are ways you can prevent it from forming on your scalp.

Be sure to brush your hair twice a day, limit how often you wear synthetic fabrics on your head (like scarves or hats), and don't be afraid to massage your scalp, especially when in the shower.


Also take steps to refrain from touching your scalp and not itching, even though it's irritated; this can lead to more irritation and a build up of dirt from your fingers.

Shampoo and style with products that don't cause itchy skin and don't wash your scalp oils away to the point of redness. You should also limit the amount of hair products you use.

Finally, reduce stress in your daily life. Take the time to relax, take a walk outside, and avoid any stressors that may have you feeling triggered.

How to Get Rid of Dandruff

Along with dandruff prevention, there are ways to get rid of dandruff and reduce irritation and inflammation on the scalp.

According to the American Academy of Dermatology Association (AAD), your race determines how often to wash your hair with both regular shampoo and dandruff shampoo.


You can also ask your doctor to prescribe a medicated shampoo, with ingredients like zinc pyrithione, salicylic acid, coal tar, selenium sulfide, ketoconazole, or fluocinolone to treat your scalp.

RELATED: The Best Tips For Using Dry Shampoo In Between Washes — For All Hair Types

Rebecca Jane Stokes is a freelance writer and the former Senior Editor of Pop Culture at Newsweek with a passion for lifestyle, geek news, and true crime.