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Dandruff or a dry scalp—which is it? We’ve likely all wondered this oft-debated question at least one point in our lives. Despite how similar these conditions are, when you look closely, you’ll notice they have specific characteristics that make them stand apart. To discover what those characteristics are, keep reading for everything there is to know about dandruff, dry scalps, what differentiates them, and how to best move forward with your scalp in mind.
Meet the Expert
- Dr. Blair Murphy-Rose is a board-certified dermatologist based in Midtown, Manhattan.
- William Gaunitz is a certified trichologist specializing in scalp health and hair growth.
- Dr. Robyn Gmyrek is a New York City-based dermatologist.
- Marina Perkovic is a stylist and scalp expert based out of Eliut Salon.
Dandruff Causes and Symptoms
First things first, let’s be clear on what dandruff actually is. According to Dr. Murphy-Rose, dandruff is a chronic condition—often considered to be a mild form of seborrheic dermatitis —that waxes and wanes over time. In its most obvious form, dandruff presents itself as noticeable white flakes.
Now that you have a general idea of what dandruff is, let’s get into the nitty-gritty in terms of causes and symptoms so that you know what to be on the lookout for.
- Overactive sebaceous glands
- Fungal growth
- Irritation from hair care products
Dandruff is often associated with dirty scalps and an overall idea of poor personal hygiene, when in reality, it can happen to anyone.
“The cause of dandruff is not entirely understood but it is often associated with excess oil production and an overgrowth of fungus, particularly Malassezia sp, on the scalp,” Murphy-Rose says. “The scalp contains an abundance of hair follicles with sebaceous glands that produce large amounts of sebum—an oily substance—creating an ideal environment for fungi to thrive in.” And when you pair that fungi with excess oil, microscopic dead skin cells that would normally slough off unnoticed, stick together in clumps that present themselves as tiny-yet-noticeable white flakes.
If you’re wondering how fungi could grow on—and become a problem for—your scalp, you’re not alone. As Gaunitz points out, scalp fungus is totally normal and it’s typically controlled by the immune system, which makes the possibility of developing dandruff less likely—though certainly not impossible.
“There are certain causes that lower the scalp immune state, like low vitamin D3 or ferritin, genetic history, an inflammatory diet, aggravating hair and scalp products, or allergies,” he explains, noting that all of these factors can play into whether or not fungus will thrive on your scalp.
If the fungus starts to get truly out of control—which can happen since the more oil is on your scalp, the more fungi will form; and the more fungi that forms, the more it will stay trapped on your scalp in said oil—it can trigger hypersensitivity, which leads to itching, further flaking, and, in some cases, redness. When this happens, what started as a mild form of seborrheic dermatitis can excel into a more serious form. But don’t worry! Dr. Gmyrek, the inflammatory condition is incredibly common and not super difficult to treat—more on that as you move further into this article.
When dandruff progresses from a mild to extreme form, Gmyrek says that it can cause skin cells to multiply more quickly than usual, which results in heavier flakes, persistent itching, and more noticeably inflammation.
Before diving into the symptoms—read: the signs to be aware of—of dandruff, it’s worth noting that, while the main cause of dandruff is the aforementioned fungal growth, the Mayo Clinic reports (and Gmyrek agrees) that stress can take a toll on your scalp health as well, and thus can be another culprit in the war against white flakes. “This ‘stress’ can be psychological—such as relationship trouble—work deadlines, etc… or it can be physical stress on your body, such as having a cold, fighting an illness, having surgery, or simply being run down,” she says.
- Itchy scalp and/or eyebrows
- Noticeable white flakes
- Potential redness
The most common sign of dandruff is when you start to notice white flakes falling from your scalp to your shoulders and back as you brush or tousle your hair. Of course, before such flakes appear, all of our experts say that itchiness will likely present itself first.
Dry Scalp Causes and Symptoms
Now that you’ve read through the key factors that play into dandruff, you might be questioning whether that’s what you’ve actually been dealing with after all. This is very common considering dandruff is often misunderstood as the definition of an itchy, dry scalp, when in reality it speaks to something more.
For this reason, it’s good to know what constitutes a dry scalp, as well. That way you’ll be able to weigh your symptoms to determine which scalp issue you’re dealing with before moving forward with treatment options.
- Inability to produce or retain moisture
- Excessive washing
- Irritation from haircare products
According to BosleyMD certified trichologist Gretchen Friese, a dry scalp occurs the same way that dry skin does: When it doesn’t produce or retain enough moisture. “Like other forms of dry skin, this can cause itching, flaking, and irritation,” she says.
When it comes to moisture, it’s important to understand that you can wash your scalp’s hydration down the drain if you shampoo it too regularly. What’s more, what you wash it with can also lead to drying—that’s why it’s so important to use well-formulated haircare products designed to hydrate your strands without weighing them down, not strip them.
Products and showering aside, Murphy-Rose, who is a clinical assistant professor at New York-Presbyterian Hospital, Weill Cornell Medical Center, says that the climate (think: seasonal and year-round; high levels of heat or cold, and low levels of humidity) and excessive sun exposure can also lead to a dry scalp, not to mention if you have a genetic predisposition to dry skin.
- Itchy scalp
- Dry hair
- Small, barely-there flakes
While flakes are much less likely from a dry scalp alone, Perkovic says that very small flakes are possible as a result of extreme dryness, just as they are on your face during the harshest seasons of the year.
The Key Difference Between Dandruff vs. Dry Scalp
Now that both conditions have their figurative cards on the table, let’s go over the key differences between the two. While both dryness and dandruff can make your scalp itch, and both can lead to even the faintest flaking, Gaunitz, who is the founder of the Gaunitz Trichology Method, says that the main difference between dandruff and a dry scalp is that dandruff is an actual medical condition. “Dandruff is caused by an elevation of fungus on the surface of the scalp, whereas a dry scalp is simply a hydration issue,” he says.
Friese adds to this, noting that, while both dandruff and a dry scalp tend to come and go, dandruff—which is a result of a fungal infection—is unlikely to disappear without treatment. “Dry scalp, however, may improve with less frequent shampooing,” she says, noting that it is possible to have both dry scalp and dandruff, which is why most people find it difficult to tell the difference between the two.
Prevention & Treatment
If you’ve gotten this far and think you may have dandruff, this section is for you. If, however, you think a dry scalp may be the culprit, feel free to skip over to the next section.
- Use a Medicated Shampoo: Gmyrek says to reach for a shampoo formulated specifically for dandruff or seborrheic dermatitis at least two times a week. “These shampoos contain salicylic acid, ketoconazole, zinc pyrithione, or selenium sulfide, and will work to decrease oil and fungus, and flakes as a result,” she says.
- Up Your Omega 3 Intake: According to Gaunitz and experts running the Cedars Sinai medical blog, omega-3s help to regulate oil production, which can in turn reduce the amount of fungal growth and flaking.
- Take Vitamin D Supplements: Speaking of supplements, Gaunitz adds that one of the best ways to prevent dandruff is to take vitamin D3 supplements. This makes sense considering, according to the American Academy of Dermatology, vitamin D helps slow the rate of rapid skin cell growth—which can be a factor in more extreme cases of dandruff and psoriasis.
- Stock Your Hair Care Routine With Tea Tree Oil: As Cedars Sinai points out, tea tree oil is anti-inflammatory and anti-microbial, making it a great option for scalp rebalancing. Thankfully, these days it's mixed into a slew of hair treatments, shampoos, conditioners, and masks.
- Try Meditation (and/or Exercise): Seriously though. High levels of stress can trigger dandruff and excessive flaking. As if you need another excuse to zen out, let this be it. Just remember: The calmer you are, the less likely a dandruff flair will be.
If you think you have a dry scalp and are looking for relief, let this be your guide.
- Try a Pre-Shampoo Scalp Treatment: When your scalp is dry, it needs all the help it can get to feel comfortable again. One of the best ways to do this is to start your haircare routine with a product designed specifically for your scalp’s comfort and wellbeing—like Drunk Elephant’s T.L.C. Happi Scalp Scrub ($36). This scrub is designed to gently exfoliate the scalp while deeply hydrating it with marula and mongongo oils. Simply apply it to dry hair before hopping into the shower, let it work its magic for 10 minutes, rinse thoroughly, and shampoo and condition as normal. Using the best-selling scalp scrub twice a week will lead to a much happier, much more moisturized noggin.
- Use a Moisturizing, Gentle Shampoo and Conditioner: Since a dry scalp can be in part due to irritation, swapping out any harsh shampoos and conditioners for ultra-gentle ones can seriously pay off. When looking for gentle shampoos, you’ll want to steer clear of fragrance and essential oils, and veer toward hydrating, soothing ingredients like aloe vera and oat milk—ultimately making Briogeo’s newest collection a dream for anyone looking to rehab their scalp.
- Eliminate Products With Alcohol as a Main Ingredient: Many haircare products are made with alcohol. It’s when alcohol is a main ingredient that it’s particularly worrisome. For this reason, when scouring for the best haircare products for your mane goals, make sure none of the ones you make room for in your routine have alcohol in the first five to 10 ingredients. Your scalp (and ends, honestly) will thank you.
- Wash Less Often: Remember, you can wash your scalp’s natural oils (read: hydration) down the drain if you shampoo too frequently. That said, try to wash no more than every other day when attempting to cater to your scalp—and always use lukewarm (not scalding hot) water when doing so. While the temperature may not seem like a big deal, when it comes to the hydration of your scalp and skin, the hotter the water, the more dried out they'll both become. Yikes. (Pst: Apply Head and Shoulders Soothing Leave-On Scalp Cream after each shower. It’s designed to make the time between washes more comfortable.)
- Add a Humidifier to Your Home: Part of having a dry scalp comes down to the climate you live in. If you live somewhere super dry—or if it’s summer or winter (aka the driest times of the year—it helps to have a humidifier to pump a little moisture back into your environment. While there are plenty of humidifiers to choose from, the Dyson Pure Humidify+Cool is the first machine to-date to be recognized by the National Psoriasis Foundation (NPF) as a solution for people with psoriasis, psoriatic arthritis, and/or individuals living with severe sensitive skin. Since psoriasis involves flaking skin—and since dry skin is associated with sensitivity—this machine is a shoo-in for anyone looking to pamper their scalp.
Dandruff and a dry scalp are often mistaken for one another but, at the end of the day, they have their own unique traits. The best way to care for either condition should it arise is to remember to treat your scalp like the rest of the skin on your body: With daily attention and loving care.
Sentiment aside, if you feel like you’ve tried everything and your symptoms aren’t getting any better, it’s best to visit your dermatologist for directions on how to proceed.