What is dandruff? Our expert decodes all the causes and how to treat it

Find yourself asking: what is dandruff? From the sources to basics about your scalp health, we answer all your dandruff queries.

Despite affecting approximately half of the world’s population, dandruff is a hair issue many people don’t like to openly talk about. Defined as flakes of skin on the scalp, this condition can be embarrassing and uncomfortable to live with. But what is dandruff?

Dandruff is the experience of flaky scalp skin that you can see in your hair or on your shoulders - Peter Bailey, Global Technical Manager, Hair Care.

If you can relate, we’re here to help. ATH sat down with Unilever’s Peter Bailey, Global Technical Manager, Hair Care, to debunk some of the most common myths surrounding this hair concern. From causes to cures, Peter weighs-in with his expert opinion on how to recognize and treat dandruff.

What is dandruff? Close up of brunette girl showing hair parting
What is dandruff? We decode your hair myths.

What does dandruff look like?

Unfortunately, dandruff can be a very noticeable scalp condition. Flakes of skin on the scalp are mostly shades of white, which makes them especially obvious if you’re sporting darker locks.

There’s not one uniform size or shape of the flakes, it depends on the condition of your scalp and how prone the skin is to shedding.

What is dandruff? Blonde girl with side parting and bun backstage
What actually causes a flaky scalp? Credit: indigitalimages.com

What causes dandruff?

As Peter reveals, “dandruff is caused by a number of factors. The presence of a micro-organism call Malassezia, (which everyone has on their scalp) is one of the most talked-about sources.”

The amount of sebum that’s present on the scalp is also another dandruff-affecting factor, as is whether or not the scalp skin of that particular person is susceptible to flaking. “This is similar to the way in which some people are prone to dry skin more than others,” verifies Peter. So, is dandruff contagious? “No,” he confirms.

What is dandruff? Girl with brunette hair profile shot with deep side parting
Keep your scalp healthy with our anti-dandruff tips. Credit: indigitalimages.com

How does your scalp health affect dandruff?

Healthy skin (including on the scalp) forms a strong protective barrier to prevent water loss and maintain the correct hydration level. “Think of it like bricks and mortar in a wall – the skin cells act as the bricks and lipids act as the mortar holding the barrier together,” Peter explains.

Disruption of the lipids in this barrier can result in water loss, leading to dry or irritated skin. One of the most common symptoms of which is flaking: AKA dandruff.

is dry shampoo bad for your hair women washing her long brown hair before curling long hair
But how do you actually treat dandruff?

How do I treat dandruff?

The most common way to treat dandruff is with an anti-fungal-containing shampoo (such as zinc pyrithione), whose primary role is to remove the Malassezia micro-organisms from the scalp.

“By removing Malassezia micro-organisms, the main source of attacking toxins is removed and the scalp skin can then start to recover and rebuild its protective scalp barrier again.”

What is dandruff Model with hair pulled back looking at camera
Do you suffer from dandruff? Credit: indigitalimages.com

What makes dandruff worse?

The drier the skin on your scalp is, the more prominent your dandruff can appear. A combination internal and external factors can disrupt the scalp skin barrier, leading to dryness.

“Internal factors can include a change in diet, stress or illness. External changes in temperature, low humidity and the use of harsh surfactants can also affect your scalp,” advises Peter.

What is dandruff front view of blonde model on bed running hands through hair
Now we’ve answered what is dandruff, stop it coming back. Credit: Rex by Shutterstock

How can I stop dandruff returning?

Maintaining your scalp’s health is an on-going process. If you have any concerns, make sure to consult a medical professional. Especially if you feel that the frequency of your dandruff or scalp health is in question.