It’s true: a hydrating cleanser and well-formulated moisturizer are fundamental to any skincare routine. But what people never mention is that hydrating your skin depends, in large part, on hydrating your body as a whole. If you don’t replace fluids and electrolytes after a sauna, for instance, you can develop dehydrated skin.
That said, most people get plenty of fluids. We’ve been drilled from a young age to drink at least eight glasses of water per day, regardless of your thirst or how much water you’re getting from other sources. (Yes: coffee, tea, and many foods provide water too!)
A better strategy is to drink to thirst, but water is just the half of it. We also need electrolytes (especially sodium and potassium) to maintain fluid balance, including in one’s skin. In fact, drinking too much water can deplete blood electrolyte levels—which your body quickly restores by procuring electrolytes from other bodily sources.
In this article, we’ll cover skin hydration basics, plus causes and remedies for dehydrated skin.
The Importance of Skin Hydration
Most bodily tissues depend on water—we’re mostly water weight, after all—and skin is no exception. In particular, water keeps the outer layer of your skin (called the stratum corneum) functioning properly.
The stratum corneum is how the world sees your skin. It’s the barrier that protects the rest of your body from the outside world. It’s also the barrier that keeps materials (like fluids) from spilling out. In fact, maintaining skin moisture depends on the ability of the stratum corneum to prevent transepidermal water loss.
Maintaining skin moisture also depends on hydration status. If you don’t consume adequate fluids and electrolytes, your skin may begin to resemble a dry husk of corn.
Beyond hydration habits, other factors influencing skin health include:
- The levels of various lipids, sugars, and proteins (glycerol, hyaluronan, water-transporting protein aquaporin-3) found in skin cells
- Genetic factors
- Micronutrient intake (zinc, selenium, and vitamin A are all crucial for skin health)
- UV exposure
- Alcohol consumption habits
- Sleep habits
Today is a deep dive on skin hydration, but don’t neglect the other factors. Skin health is a holistic endeavor.
Dry Skin vs. Dehydrated Skin
According to several popular websites, dry skin is distinct from dehydrated skin. The claim is: dry skin is a skin type caused by low sebum levels, while dehydrated skin is a condition of low skin moisture.
But the medical literature doesn’t support this distinction. In one paper published in The Journal of Dermatological Treatment, the authors report that “dry skin is a common condition that is attributed to a lack of water in the stratum corneum.”
Note how dry skin is labeled a “condition,” not a skin type, and that poor skin moisture is the proximate cause. Other researchers point out that “skin requires a water content of 10-15% to remain supple and intact.” Again, the focus is on skin hydration.
Basically, healthy skin is synonymous with hydrated skin. In turn, hydrated skin depends on many factors, including your hydration habits, natural skin oils, and nutritional status.
In other words, dry skin is dehydrated skin—and vice versa. This doesn’t mean that dehydration is the only cause of dry skin, but it does suggest that we should stop viewing the two as totally distinct and separate.
Symptoms of Dehydrated Skin
Dry skin is a well-documented dehydration symptom. Other symptoms of dehydrated skin include:
- Itchy skin
- More pronounced wrinkles and fine lines
- Cracked lips
- Dark circles under the eyes
- A lack of color or dullness to the skin
These symptoms suggest something is wrong with your skin hydration. They don’t necessarily mean you need more fluids.
To triangulate, look for other dehydration symptoms like thirst, dark urine, or feelings of fatigue. In particular, thirst and dark urine are clear signs to drink more water. But be sure to include sodium in that water. I’ll explain why in a bit.
What Causes Dehydrated Skin?
The causes of dehydrated skin are coincident with the causes of dehydration. When someone becomes dehydrated, it’s generally due to excess water losses through the gut, urine, skin, or breath. Some examples will help illustrate.
- Diarrhea, vomiting, and simple digestion all deplete body water.
- Kidney issues, diuretics, or any intervention (like a low-carb diet or fasting) that has a diuretic effect cause significant urinary water losses.
- The more you sweat, the more water and sodium you lose. Why do you think exercise demands extra hydration?
- Physical activity (especially in elevated or cold climates) also increases respiratory water losses.
What about alcohol? That belongs in the urine losses category. Yes, alcohol suppresses a fluid-retention hormone called vasopressin. And suppressed vasopressin (also called antidiuretic hormone) is why you need umpteen bathroom trips after a few cocktails.
All those pee breaks dehydrate you. The next morning, your skin pays the price.
Notice how I didn’t mention insufficient fluid intake as a primary cause of dehydration. With some exceptions (age-related mobility issues, cold climates, elevation), most healthy people do a fine job drinking enough water.
That’s because we have a brilliant mechanism called thirst. Thirst tells us when to drink and when to stop drinking. And the “when to stop” is just as important as the “when to start.”
Why? Because more water is not always better. Not knowing when to stop can lead to overhydration, dilute your blood sodium levels, and leave you hanging with a slew of low sodium symptoms.
Sodium and Hydration
If you want to stay hydrated for energy, cognition, and skin health, you need to get enough sodium. Sodium is the yin to water’s yang. Both are essential for hydration.
The mistake most people make? They drink lots of water while diligently limiting salt consumption. After all, the propaganda says that water is “healthy” and sodium is “bad for your heart.”
Here’s the thing. Water is healthy, but overhydration can cause a dangerous low sodium condition called hyponatremia. And while crazy high salt intakes do elevate blood pressure, limiting sodium also elevates blood pressure. My point is that most healthy people need more salt, not less.
How does this relate to skin health? It relates because sodium regulates fluid balance throughout your body. In other words, sodium keeps water balanced in your blood vessels, sweat, tears, and skin.
Hydration Tips to Restore Dehydrated Skin
If you have dehydrated skin, a fancy cream won’t fix it alone. Like much of our modern health issues, dehydrated skin oftentimes originates in our diet. You need to fix the problem from the inside out. Here are some simple tips to do that.
#1: Be mindful of dehydrating situations
Dehydrating situations increase your risk of dry skin. Adjust your behavior (and hydration strategy) accordingly.
For instance, if you’re playing a tennis match on a humid afternoon, you’ll want to bring along plenty of electrolyte water. And if you’re sick with a stomach bug, you’ll want to replace fluids, sodium, and potassium as best you can. Drinking beyond 1-2 alcoholic beverages will also increase water and electrolyte losses. If you’re curious to learn more, read this hangover hydration article by LMNT co-founder Luis Villaseñor.
#2: Drink when thirsty
We already covered this, but I want to hammer it home. For most people most of the time, drinking to thirst is enough to prevent dehydration.
Thirst is controlled by the hypothalamus, an ancient brain region that regulates a host of automatic functions. To heed thirst is to heed the wisdom of your body.
Ignoring thirst is the opposite of wisdom. If you don’t drink when thirsty (rare), you’re guaranteed to become dehydrated. And if you drink past thirst (common), you’ll enter the unhappy realm of low sodium.
#3: Get enough electrolytes
If you neglect electrolytes like sodium and potassium, your fluid balancing system won’t work. As a result, blood flow, brain health, and skin hydration will suffer.
Getting enough electrolytes means:
- Eating electrolyte-rich foods like leafy greens, avocados, and nuts.
- Salting your meals like you mean it.
- Supplementing when necessary. (Pro tip: use the Cronometer app to log your meals and see which vitamins and minerals you need to supplement.)
Oh and one last thing: drink electrolyte water!
#4: Bring a bottle of electrolyte water
I always keep a bottle of electrolyte water handy. Each stick of LMNT contains 1 gram of sodium, 200 mg potassium, and 60 mg magnesium to replenish your electrolytes. Just toss 1 stick of LMNT into 16–32 ounces of water to suit your taste. I live an active low-carb lifestyle, so I need those fluids and electrolytes to stay hydrated from the inside out.
Let’s summarize now. I believe hydration habits play a big part in how our skin looks, but I recognize that hydration isn’t everything. We also need adequate rest, a nutrient-dense diet, and many other things to keep our skin from resembling a catcher’s mitt.
As with all aspects of health, skin health is holistic. You need to do a lot of things right. Hydration is just the beginning, but it’s the foundation upon which healthy skin is built.