What Causes Dandruff?

Malassezia normally lives on the scalp. In some people, the scalp reacts to the yeast and the oils around it, speeding up shedding and causing flakes. The flakes may be white, grey, or yellowish, with itching or mild redness. Dandruff can be more noticeable when the scalp is oily, but washing the hair does not cause it and it is not a sign of poor hygiene.

Dandruff and seborrheic dermatitis overlap. Seborrheic dermatitis usually causes more persistent inflammation and may affect the eyebrows, ears, sides of the nose, or beard area as well as the scalp.

Use an anti-dandruff shampoo according to its label, allowing it to remain on the scalp for the recommended contact time before rinsing. Work it into the scalp rather than only the hair lengths. Once flakes settle, some people need ongoing use to keep symptoms controlled. Avoid scratching, very hot water, and harsh styling products if they worsen irritation. A pharmacist or dermatologist can help choose an active ingredient for your symptoms.

Seek medical advice if the scalp is very inflamed, painful, crusted, oozing, or losing hair in patches, or if flakes affect the face and do not settle with appropriate shampoo use. An evaluation is also useful when symptoms repeatedly return, because psoriasis, eczema, contact dermatitis, and fungal conditions can resemble dandruff.

Ask whether this is dandruff or seborrheic dermatitis, which shampoo ingredient fits your scalp, how often to use it, and whether another condition could explain redness, thick scale, or hair changes.