Dandruff: Common Causes and Care

What dandruff is

Dandruff is a common condition in which the scalp sheds visible flakes of skin. Everyone sheds skin cells all the time, but with dandruff the shedding is more noticeable, and the flakes may be accompanied by itching. The flakes are often white or yellowish and may appear larger or oilier than the fine dust of normal shedding.

Dandruff is not caused by poor hygiene, and it is not contagious. It tends to come and go, and for many people it flares in particular seasons or during stress. Exactly why it happens is not fully understood, but several factors are commonly discussed.

Common contributing factors

• Yeast on the scalp. A type of yeast that lives on most people’s scalps is often discussed in connection with dandruff. It normally causes no trouble, but in some people the scalp seems to react to it or to substances it produces from natural oils.
• Oil production. Dandruff is often seen where oil glands are active, which is one reason it can be more noticeable in teenagers and adults than in young children.
• Individual sensitivity. Some scalps simply react more strongly than others, and this is partly personal and partly inherited.
• Infrequent washing. Skin cells and oil can build up and appear as flakes. Washing too aggressively can also irritate the scalp, so more is not always better.
• Product reactions. Hair dye, styling products or shampoo ingredients can irritate the scalp in some people. A reaction to a product is a different issue from dandruff, though the two can look alike.
• Cold, dry weather and dry indoor air. Dry conditions can make flaking more visible.
• Stress and tiredness. Many people report flares during stressful or sleep-deprived periods, though the relationship varies. Some also notice a link with sleep and stress.

Dandruff, dry scalp or something else

Two people can both say they have a flaky scalp and mean different things.

• Dry scalp often involves small, dry, whitish flakes. The scalp may feel tight, and the skin elsewhere may be dry too, especially in winter.
• Dandruff often goes with a scalp that is a little oily, and the flakes may be larger and slightly greasy.
• Seborrheic dermatitis is a more inflamed form. The scalp may be red with scaly or greasy patches, and it can also affect areas such as the eyebrows, sides of the nose or behind the ears. Seborrheic dermatitis is a recognized skin condition worth getting checked if it is persistent.
• Other conditions. Eczema basics, scalp psoriasis, contact dermatitis and fungal infections can all produce scale or itch, and they are managed differently. This is one reason that a persistent, thick or very itchy scalp is worth showing to a professional rather than treating by trial and error.

General care that often helps

Approaches vary, and there is no single method that works for everyone.

1. Wash regularly with a gentle routine. Many people with flaking do better washing more often, for example several times per week, than waiting until flakes build up. Use fingertips, not nails, and massage the scalp itself rather than just the hair.
2. Rinse thoroughly. Leftover shampoo or conditioner can irritate the scalp.
3. Consider an anti-dandruff shampoo. Many over-the-counter shampoos for flaking contain well-known types of active ingredients that are designed to reduce flaking and the yeast on the scalp. Follow the label, which usually involves leaving the lather on the scalp for a few minutes before rinsing. Using the shampoo regularly for several weeks is often needed to judge whether it helps. If one type does not seem to help after a fair trial, some people alternate or try another type, but check the label rather than guessing.
4. Be gentle with the scalp. Avoid scratching and picking at flakes. Scratching can cause small wounds and irritation, which makes flaking worse.
5. Use styling products sparingly. Heavy products can build up on the scalp. If you suspect one is irritating you, stop using it and see whether things settle. Fragrance sensitivity can be a factor in some people.
6. Protect the scalp from sun and wind. A sunburnt scalp can peel and mimic flaking.

Dandruff often improves with these steps, but it can return, and ongoing maintenance may be needed. It is a long-term pattern for many people rather than a one-time problem to be solved.

What not to do

• Do not scrub hard with a brush or nails to remove flakes.
• Do not apply undiluted essential oils or home mixtures to an irritated scalp, since some can aggravate it. Even natural products are known to cause reactions in some people.
• Do not assume more shampoo means faster results. Heavy use of harsh products can dry and irritate.
• Do not ignore changes. A scalp that suddenly worsens should be looked at.

When to ask for advice

Consider speaking to a doctor, pharmacist, dermatologist or other qualified health professional if:

• Flaking continues despite several weeks of consistent care
• The scalp is very red, swollen, painful, oozing or has crusting
• You see thick, silvery or heavily scaled patches
• Itching is severe or disrupts sleep
• There are patches of hair loss or broken hair
• The rash spreads to your face, ears or body
• A child or infant has persistent scaling, since some patterns, such as cradle cap, are common but should still be checked if severe

This article is general information and not medical advice. Dandruff itself is usually harmless, but because several different conditions can look alike, a professional can help work out what is going on when simple measures do not work.