If you’re wondering what causes dandruff and how to treat it, you’re in the right place. You’re also not alone — dandruff is a very common skin condition that affects people of all ages, races, and sex.
Dandruff needs almost no introduction. If you’ve watched TV in the last twenty years, you’ve likely seen a commercial where a man finds the shoulders of his black T-shirt covered in white flakes and ponders what to do about it.
If you’re wondering what causes dandruff and how to treat it, you’re in the right place. You’re also not alone — dandruff is a very common skin condition that affects people of all ages, races, and sex.
We’ll cover what dandruff is, its causes, and — most importantly — what you can do to treat or prevent it.
You’re probably familiar with what dandruff looks like, but here are some signs and dandruff symptoms to keep an eye out for:
Itchy scalp. Your scalp may feel itchy or irritated.
Yellow or whitish flakes. The most obvious sign of dandruff is yellow or whitish flakes showing up in a person’s hair, on their bed pillow, or on their clothes.
Scaly patches on the scalp. You might notice scaly or crusty patches of skin, particularly in areas with excess oil production.
Dryness or oiliness on the scalp. One of the vexing things about dandruff is that it can make the scalp feel either excessively dry or oily, depending on the underlying cause.
Redness or irritation. The skin on the scalp may appear red or inflamed due to irritation, especially if the dandruff is caused by seborrheic dermatitis.
Worsening in cold, dry weather. Symptoms of dandruff often get worse in the winter or in dry, cold conditions, when the scalp is more likely to become dry.
Though most dandruff looks similar, a few things can cause it:
Malassezia buildup
Seborrheic dermatitis
Oily skin on the scalp
We’ll explain these in more detail below.
Malassezia is a harmless fungus everyone has on their scalp — it’s part of the skin’s normal flora. It’s actually an umbrella term for several types of fungus.
But if everyone has Malassezia, why doesn’t everyone have dandruff? Great question.
Dandruff is caused specifically by an overgrowth of Malassezia, meaning there’s too much of it on the scalp. A 2014 study found that a high density of Malassezia species on the scalp was associated with a higher severity of dandruff.
While dirty or oily hair on its own isn’t enough to cause dandruff, Malassezia feeds on sebum — so more oil equals more scalp fungus.
After Malassezia essentially eats the fatty acids in sebum, it leaves behind a byproduct called oleic acid. Research shows that some people are more sensitive to oleic acid — and to get rid of it, their dead skin cells turn over quickly, causing flaking and shedding.
Though Malassezia is a leading factor in why seborrheic dermatitis develops, other things can cause it.
Seborrheic dermatitis is a common skin disorder worldwide. It affects up to 70 percent of infants (it’s called cradle cap in babies) and roughly 12 percent of the general population. Seborrheic dermatitis is a common cause of dandruff.
Yeast is a common cause of an oily scalp — but not the only one.
Here’s what can cause oily buildup on the scalp:
Not shampooing regularly
Not using enough shampoo
Allowing sweat to accumulate
Not thoroughly rinsing out hair products
Some men have excess oil on their scalps, and while their hair may look a little greasy, they won’t get dandruff. But if you have too much yeast on your scalp paired with this oil buildup, it can result in white or yellow flakes.
Dandruff is tricky because it can be caused by one thing or some combination of oil secretion, fungal colonization, and an individual susceptibility to the condition.
Risk factors that make someone more likely to have dandruff or seborrheic dermatitis include:
Chronic stress. High stress levels can worsen dandruff by affecting your immune system and scalp health.
Genes. There’s not one gene associated with dandruff, but findings from 23andMe identified 487 genetic markers associated with dandruff. Research has also found that some forms of seborrheic dermatitis and dandruff can be inherited. If your parents or other close family members have dandruff, you may be more likely to get it.
Hormones. Hormone levels influence sebum production. So during periods of hormonal change (puberty, for example), it’s not uncommon to see dandruff flare-ups.
Nervous system disorders. Parkinson’s disease and other nervous system disorders can affect oil production and how much or little a person sweats, which can contribute to dandruff.
A weakened immune system. Those with weakened immune systems (caused by HIV infections, chemotherapy, obesity, or certain autoimmune disorders) are more prone to dandruff. But the exact reasons aren’t entirely clear.
Living in a dry climate. Low temperatures and a lack of humidity also contribute to dandruff, which is why it often flares up in winter.
Poor hair hygiene. Infrequent washing or not getting shampoo on the scalp can allow oil and skin cells to build up, contributing to dandruff.
Age. Research shows that dandruff often starts during puberty, reaches “peak incidence and severity” around the age of 20, and becomes less prevalent among folks over 50.
Sex. Dandruff is more prevalent in men than women.
Since dandruff isn’t a serious condition, diagnosis is generally quick. And treatment can begin right away with medicated shampoos or lifestyle adjustments.
Here’s how dandruff is typically diagnosed by a healthcare professional:
Lifestyle and medical history overview. Your healthcare provider may ask about your symptoms, when they began, and any other contributing factors like diet, lifestyle, or stress levels. They might also ask about what products you use in case they suspect an allergic reaction that mimics dandruff.
Scalp examination. Your provider will closely inspect your scalp for white or yellowish flakes and other signs of irritation, such as redness or swelling. They’ll also check for oily patches or dry skin.
Ruling out other conditions. A medical professional will look for signs of more serious skin conditions that can resemble dandruff, such as psoriasis or eczema. In rare cases, a skin or scalp biopsy might be taken if there’s doubt about the diagnosis.
We should note that you can treat dandruff without seeing a healthcare provider. But in cases of severe dandruff or dandruff that won’t go away, you’re wise to check with a medical professional.
Dandruff is fairly easy to treat. It shouldn’t require much more than switching up your shampoo or making simple lifestyle tweaks. Here’s how to treat dandruff.
That guy in the dandruff commercial was onto something. One of the easiest and most effective ways to clear up a flaky scalp is to lather up with anti-dandruff shampoo.
Shampoos with active ingredients like pyrithione zinc, ketoconazole, selenium sulfide, coal tar, and salicylic acid are the gold standards for treating dandruff. And they typically work for all hair types.
The best shampoos for dandruff are formulated with:
Pyrithione zinc and salicylic acid. Our dandruff detox shampoo contains 1% pyrithione zinc and salicylic acid. This medicated shampoo reduces buildup on the scalp, calms itchiness and irritation, treats flaking, and moisturizes. A 2018 study found that zinc pyrithione shampoo and scalp lotion improve symptoms of seborrheic dermatitis.
Ketoconazole. Ketoconazole has antifungal and anti-inflammatory properties. According to research, a 2% strength seems to be the sweet spot to decrease Malassezia colonization.
Salicylic acid and sulfur. Shampoos with salicylic acid and sulfur help loosen scales so they can be washed off.
Coal tar. Dermatologists sometimes suggest coal tar shampoos for treating dandruff and redness caused by seborrheic dermatitis. However, they aren’t widely recommended because coal tar can cause irritation and increased sun sensitivity. (Using it once or twice a week might be a good cadence to minimize irritation.)
Selenium disulfide. One study found that using selenium disulfide shampoo for four weeks “significantly improves dandruff and seborrheic dermatitis.”
Follow the directions closely to get the most out of anti-dandruff hair washes. Many advise leaving the shampoo on for a few minutes before rinsing. Other formulas are meant to be used only a few days a week to avoid over-drying the scalp.
If you’re not seeing improvements in dandruff, contact a dermatologist or another healthcare professional. They can determine if you have dandruff or another scalp condition like psoriasis, eczema, tinea capitis (scalp ringworm), or contact dermatitis, which can also cause flaking and itchiness.
If you’re partial to natural remedies (or don’t feel like going to the drugstore), these at-home solutions show promise in treating dandruff.
There’s a fair amount of research backing tea tree oil as a natural remedy for dandruff. However, none of the studies are super strong — many had small sample sizes, lacked a control group, or were only done on animals.
Here’s what we know about tea tree oil for dandruff:
Tea tree oil might be a gentle, effective option. A review of several studies showed that a shampoo containing 5% tea tree oil was well-tolerated and seemed effective in treating mild to moderate dandruff.
It’s a natural fungus remedy. A 2021 study found using tea tree oil shampoo with natural antifungal properties might help reduce dandruff. That said, the shampoo used in the study also contained sodium lauryl sulfates and salicylic acid, so it’s hard to give all the props to tea tree oil.
You can buy shampoos already formulated with this essential oil. Or consider adding a few drops of pure tea tree oil to your existing shampoo.
One eight-week study found that applying coconut oil directly to the skin decreased symptoms of atopic dermatitis (eczema) by 68 percent.
In a separate study with 140 women, coconut oil applied to the scalp improved the scalp microbiome, which could help reduce dandruff.
Calming aloe vera is a hero ingredient for addressing various skin problems. Beyond soothing sunburn, it may benefit hair health. A 2015 study suggested that its antibacterial and antifungal properties could help prevent dandruff.
Look for shampoos containing this ingredient, or apply aloe vera gel directly to your scalp.
Looking for a dandruff treatment on the fly? Aspirin contains salicylic acid — it’s what makes the drug anti-inflammatory. For that reason, salicylic acid is often found in acne treatments and anti-dandruff shampoos.
If you’re in a pinch or don’t feel like running to the drugstore, you could try crushing one or two aspirin tablets and mixing them into your normal shampoo.
You may not be able to completely prevent dandruff, but some simple things might help stop it before it starts.
Here are our best tips for dandruff prevention:
Wash your hair regularly
Use anti-dandruff shampoo
Keep your scalp moisturized
Rinse out styling products well
Avoid too much sun exposure
Be mindful of your diet
Know your options
Find more detailed guidance below.
Use a mild shampoo to cleanse your scalp and remove excess oil, dirt, skin cells, and haircare products that can contribute to dandruff buildup. Avoid overwashing, which can dry out the scalp.
If you’re prone to dandruff, use medicated shampoos containing active ingredients like zinc pyrithione, selenium sulfide, salicylic acid, or ketoconazole. Rotate between different shampoos for better results.
Ensure your scalp stays hydrated, especially in cold or dry weather. Use a gentle conditioner or scalp oil if the skin beneath your hair tends to dry out.
Good news: Hair products don’t directly cause dandruff. So you can keep your trusty haircare arsenal — just be sure to rinse thoroughly to prevent residue buildup.
As mentioned, product buildup can become dinner for Malassezia bacteria. Beyond using dandruff shampoo, it can help to occasionally use a clarifying shampoo containing extra soap ingredients to reduce buildup and get your scalp super clean.
If you have dandruff, you’ll probably want to get a little bit of sun — but not too much. We’ll explain.
Some research shows that UVA and UVB rays from the sun can actually help treat seborrheic dermatitis. How? They kill yeast. But you don’t want to get a sunburn, which can make scalp flaking worse (among many, many other reasons to avoid sunburn).
Certain dandruff shampoos, especially those containing coal tar, can make skin more sensitive to the sun (you may see it called “photosensitivity” on a warning label). So it’s vital to wear protective hats and apply broad-spectrum scalp sunscreen if needed.
A large 2019 study with over 4,000 participants found that high fruit intake was associated with a lower instance of seborrheic dermatitis. Meanwhile, those who ate diets high in added sugar and processed foods were more likely to have the scalp condition. Pass the strawberries, please!
Eating foods rich in protein, zinc, iron, biotin, and various other vitamins and minerals is crucial for overall hair health.
Is dandruff bad? Not really — a flakey scalp doesn’t mean there’s anything wrong with your overall health or point to any serious medical conditions. But it can be irksome to deal with.
If you’re noticing symptoms like an itchy scalp, flakes of skin on your clothes, or scaly patches on your scalp, you’re probably wondering what you can do about dandruff.
Here’s what to keep in mind whether you have severe or mild dandruff:
Dandruff manifests as large, oily, or crusty scales and flakes. It’s caused by several factors, most commonly an overgrowth of a yeast known as Malassezia.
Dandruff is easy to treat. Over-the-counter and prescription shampoos containing different active ingredients (such as pyrithione zinc, salicylic acid, and ketoconazole) are designed to treat the fungus largely responsible for dandruff.
Speak to a dermatologist or another healthcare professional if your dandruff worsens or persists after treatments. More serious skin conditions like tinea capitis or scalp psoriasis can mimic dandruff, so your provider can help you figure out what’s happening.
Want to dive further into this topic? Check out our detailed guide on getting rid of dandruff, and find out whether dandruff causes hair loss.
This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment. Learn more about our editorial standards here.