Dry skin is short on oil. Dehydrated skin is short on water. Dry skin is a skin type you mostly live with: rough, flaky, sometimes itchy. Dehydration is a temporary state any skin can get into, even oily skin: it looks dull, feels tight and shows fine lines more. Dry skin needs richer creams and gentler washing. Dehydrated skin needs water held in: a humectant like glycerin or hyaluronic acid on damp skin, sealed with a moisturizer. Lots of us, especially in winter, have a little of both.
I hear this one every fall. Someone tells me their face is "so dry," and then in the same breath says it's oily by lunch. That sounds like a contradiction, but it usually isn't. Dry and dehydrated are two different things, and once you know which one you're dealing with, it's a lot easier to know what to change.
What's the difference between dry and dehydrated skin?
The simplest way I've seen it put comes from New York dermatologist Dr. Brendan Camp: "dry" means your skin is lacking oil, and "dehydrated" means it's lacking water.
- Dry skin is a skin type. Your skin just doesn't make much oil. Genetics play a big part, and skin tends to make less oil as we get older. It's the skin you have most of the year.
- Dehydrated skin is a condition. It comes and goes. Water is leaving your skin faster than it's being replaced, because of dry air, wind, cold, hot showers, a hard workout or just a long day. Any skin type can get dehydrated, including oily skin.
How can you tell which one you have?
The signs overlap, but they lean in different directions:
- Dry skin tends to look and feel rough or flaky, sometimes with small white flakes, redness or itch. It can feel that way most of the year.
- Dehydrated skin tends to look dull and tired and feel tight. Fine lines look more obvious than usual, and under-eye shadows can look darker. It often feels worse after a bad night's sleep, a long flight or a hot, dry day.
There's also a simple at-home check people use, often called the pinch test. Gently pinch a little skin on your cheek and let go. If it wrinkles and is slow to bounce back, your skin may be low on water. It's not a diagnosis, just a clue.
Oily but tight? That's the classic sign of dehydrated skin. Your face can make plenty of oil and still be short on water. Stripping it with harsh cleansers usually makes it feel tighter, not less oily.
What causes each one?
Dry skin comes mostly from your genes and age, and it gets worse with things that strip oil away: hot water, long showers, over-exfoliating and harsh soaps. Cold weather, wind and dry indoor heat make it worse. (Here in Idaho, January is not kind to anybody's hands.)
Dehydrated skin comes from water loss: dry air, heaters and air conditioning, wind, sun, heavy sweating, and sometimes not drinking enough. Alcohol and a lot of caffeine can play a part too.
What helps dry skin?
- Go richer. Creams and balms usually do more for dry skin than thin lotions. Ingredients like shea butter, plant oils and ceramides help hold on to what your skin has.
- Wash gently. Warm water, not hot. Shorter showers. A gentle cleanser, and you don't need to scrub.
- Moisturize while you're still damp. Right after you wash, before your skin dries all the way.
- Go easy on exfoliating. Once or twice a week is plenty for most dry skin.
What helps dehydrated skin?
- Use a humectant. Humectants pull water into the top layer of skin. Glycerin and hyaluronic acid are the most common. Put them on slightly damp skin. I wrote more about how hyaluronic acid works.
- Seal it in. A humectant on its own can let that water slip right back out, so follow it with a moisturizer.
- Stop stripping. If your face squeaks after you wash it, that cleanser may be too harsh for you.
- Drink water and eat your fruits and vegetables. It helps if you've been running low, though a glass of water won't fix skin that's losing water to dry air. Do both.
- Run a humidifier, especially in winter when the heat is on.
One more tip from Dr. Camp: if your skin is dehydrated, it's more easily irritated, so it can be a good time to take a break from strong products like retinol until it feels comfortable again.
Can you have both?
Yes, and in winter most of us do. Dry indoor heat pulls water out of skin, and cold wind and hot showers strip oil. So the answer for most people is to do a little of each: wash gently, put a humectant on damp skin, and seal it in with something richer. That's really all a good routine is. Here's a simple face routine with the four steps most people need, and what to look for in a moisturizer for dry skin.
If your skin stays itchy enough to keep you up at night, cracks, looks infected or keeps coming back no matter what you change, it's worth seeing a dermatologist. Sometimes "dry skin" is something else.
What we use in our house
The Face System
Oil cleanser, face bar, a plant-oil serum with a touch of glycerin, and our Day + Night Face Moisturizer with shea butter, aloe and goat milk. Press the serum onto slightly damp skin, then seal it in with the moisturizer. Our face bar cleans without stripping your face of its oils, so skin feels soft and comfortable, not tight. Four simple steps, made in small batches on our Idaho farm.
See the Face System →
Lauren Stewart makes Tyme Soap by hand on our family farm in Idaho, with milk from our own goats.
