Dandruff is a common condition that causes flakes of skin in the hair and on the scalp. The scalp may also feel dry or itchy. Dandruff is not contagious, is not usually harmful and is not caused by poor hygiene.
What can cause dandruff?
Dandruff is often linked to seborrhoeic dermatitis and to the way the skin responds to a yeast that normally lives on the scalp. Cold weather and stress may make symptoms worse. Similar-looking symptoms can also be caused by eczema, psoriasis, contact dermatitis or a fungal infection of the scalp.
Treatment
An anti-dandruff shampoo is usually the first treatment. Products may contain ingredients such as ketoconazole, selenium sulphide, zinc pyrithione, salicylic acid or coal tar. Available ingredients differ between countries.
- Follow the product instructions, including how long to leave the shampoo on the scalp.
- Use it regularly for several weeks before deciding whether it helps.
- If one type does not work, ask a pharmacist about trying a product with a different active ingredient.
- Avoid scratching, as this can damage the skin and increase irritation.
Some people need occasional maintenance treatment after symptoms improve. Speak with a pharmacist or clinician before using medicated products on a young child, during pregnancy, or if you have another scalp condition.
When to seek medical advice
See a healthcare professional if symptoms have not improved after about four weeks of correct anti-dandruff shampoo use, or if the scalp is very itchy, painful, red or swollen. Medical assessment is also appropriate if flaky patches affect the face or body, there is patchy hair loss, or you are unsure of the diagnosis.
Seek prompt medical help if the scalp becomes increasingly painful, warm or swollen, or if there is pus or fever, as these can be signs of infection.
Sources
Reviewed: 28 August 2026