Wondering what causes xerosis (or dry skin, as we commonly know it)? Put simply, dry skin happens when your skin barrier loses too much moisture or doesn’t have enough natural oils to hold onto.
If we zoom in a little, your skin barrier is made up of skin cells and lipids (fats) that act like a seal. When that seal weakens, transepidermal water loss (TEWL) increases. And while it’s normal for the skin to lose water through TEWL, too much moisture loss can cause dryness, and even sensitivity and reactivity. The more water slips out, the tighter, rougher, and itchier your skin feels.
So what weakens your barrier in the first place? Normally, it’s everyday things: cold weather, long hot showers, aging, harsh products... In most cases, the causes of dry skin build up over time rather than happen overnight.
What Causes Dry Skin?
Dry skin rarely has one single trigger. It’s usually a few things that gradually stack up.
Maybe winter air dries you out. Then you turn up the heat indoors. Then you start a new exfoliating serum because your skin looks dull. Suddenly you’re dealing with flakes on your cheeks and tightness along your jawline.
Your barrier can handle a lot. Until it can’t.
Once it’s compromised, water escapes faster, and your skin starts sending signals: tightness, flaking, rough texture, itchiness… Your skin barrier is overwhelmed. It’s losing water faster than it can replace it.
Environmental Causes of Dry Skin
Your skin is your first line of defense. It takes the hit from whatever’s happening outside. And sometimes, it shows it.
Cold Weather and Low Humidity
Winter is one of the biggest triggers. Cold air holds less moisture, so when winter hits and humidity drops, your skin loses hydration faster.
This is one of the biggest causes of dry skin on the face, because it’s constantly exposed. Lips chap. Hands crack. Cheeks get that windburned look. And it’s all more than likely to have been caused by the weather.
Wind and Climate Exposure
Wind physically strips away the skin’s surface lipids that help seal moisture in.
So, if you’re outside a lot, that constant exposure can leave your skin feeling rough and even flaky. Then makeup clings to dry patches. And moisturizer seems to disappear faster than usual.
That’s barrier stress in action.
Indoor Heating and Air Conditioning
We love comfort. And there’s nothing like coming into a warm home in the winter, or having a blast of cool air in summer… But both indoor heating and air conditioning lower indoor humidity.
If you spend most of your day in climate-controlled air, your skin is losing moisture for hours at a time. It doesn’t feel dramatic. But your skin will start to feel persistently dry.
Lifestyle Habits That Can Lead to Dry Skin
Let’s take a look at our routines, because our daily habits can also contribute to dry skin.
Frequent Hot Showers and Baths
Hot water feels incredible. It’s comforting. It relaxes your muscles. It clears your head.
But it also dissolves the natural oils that protect your skin.
The hotter and longer your showers are, the more lipids you’re washing away. Without those oils, or even with lower levels, TEWL increases. If your skin feels tight the moment you step out and reach for a towel, that’s your barrier waving a little SOS flag.
Harsh Soaps and Cleansers
That squeaky-clean feeling? It’s often a sign your skin barrier has been stripped, not that it’s been well cleansed.
Strong foaming cleansers, sulfates, and heavily fragranced formulas can all disrupt your natural lipid layer, which can lead to that “squeaky” feel. And this is one of the most overlooked causes of dry facial skin.
At First Aid Beauty, we’re intentional about barrier-first formulations. We’ve developed gentle cleansers with soothing ingredients like colloidal oatmeal to help calm and replenish rather than strip while cleansing. Ultra Gentle Cream-to-Foam Face Cleanser with Colloidal Oatmeal + Glycerin is a great daily cleanser for dry skin and is even gentle enough for sensitive skin. It’s non-stripping and pH balanced to effectively cleanse the face and maintain the skin’s natural acidity to keep sensitive and dry skin soft and supple. Follow up with Ultra Repair Cream, our barrier-building formula that provides 24-hr hydration.
Over-Exfoliation and Active Skincare
When an exfoliating product works, it’s tempting to use it more often. After all, who doesn’t have glow goals?
But overusing retinoids, AHAs, or BHAs can thin and weaken the outermost layer of your skin. The result? Flaking around the nose. Stinging when you apply moisturizer. Redness that lingers.
Actives aren’t the enemy in themselves. Overdoing them is. Healthy skin is about balance: supporting your barrier with ceramides, oatmeal, and nourishing emollients, combined with using active ingredients thoughtfully.
Skin barrier strength first. Then actives.
Age-Related and Physiological Causes of Dry Skin
As we age, our skin changes. That’s purely biological - we all experience internal and external shifts as we get older.
Reduced Oil Production With Age
As we age, sebum production declines. And less oil means less natural lubrication.
Dryness becomes less seasonal and more constant. What used to show up in winter may now linger year-round.
It’s not a flaw. It’s physiology. And it’s one of the most common causes of very dry skin, especially on the legs and arms.
Hormonal Changes
Hormones influence oil production and hydration levels. So when important life stages happen, like the menopause for example, they can bring noticeable shifts in your skin’s texture and moisture.
Many people describe their skin during these phases as “suddenly sensitive”. That’s often the barrier adjusting to internal changes.
Medical Conditions Linked to Very Dry Skin
Most dry skin is related to environment or routine. But in some cases, persistent or severe dryness can be associated with underlying health conditions.
If your dryness feels extreme, unexplained, or accompanied by other symptoms, it’s important that you reach out to a healthcare professional.
Thyroid Conditions
Thyroid imbalances can affect how your body regulates moisture and oil production. Your skin may feel unusually dry or rough. Only a medical provider can diagnose and manage thyroid concerns.