The cause of dandruff is a naturally-occurring microbe on the scalp called Malassezia Globosa. 

You’ll find it on everybody’s scalp, although it will only cause dandruff in around 50% of people.

Here’s how it works:

1. Malassezia globosa feeds on natural scalp oils called sebum – this oil is what keeps yourhair and scalp moisturized
2. As the sebum is broken down, it produces a by-product called oleic acid
3. 1 in 2 people are sensitive to oleic acid and the scalp responds by becoming irritated
4. In response to the irritation, the scalp starts to become inflamed, red and itchy
5. The body signals to the brain to shed skin cells faster than usual – essentially, an attempt to shed the irritant.This shedding of skin is what causes visible flakes to appear on the scalp, often falling off onto your shoulders

Other factors that can affect dandruff

While the root cause of dandruff is always the same, there are certain factors that can exacerbate a problem or make it seem worse.

These include seasonal factors in summer and winter, external irritants like pollution and damage caused by our own actions such as too much heat-styling the hair.

Find out what could put you at risk of a dandruff flare-up:

• Can using the wrong shampoo cause dandruff?