What Happens to Your Skin When You Don’t Drink Enough Water in the Day

Many people think of hydration in terms of thirst, but your skin can also reveal when you’re dehydrated. “Hydration is one of the quiet power players in healthy, resilient skin,” says Oben Ojong, D.O., FAAD. “All the cells in our body need water to function optimally, and that includes our skin cells.”

While topical products like moisturizers can support skin hydration, drinking enough water is equally important for overall skin health. This isn’t just about appearance—dehydration can affect your skin’s function, too. For this article, we spoke with two dermatologists to explain how dehydration impacts skin health and share strategies to up your water intake.

Why Water Matters for Skin Health

Two-thirds of your body is water, and a portion of that water resides in your skin cells. “In the short term, when your body isn’t getting enough water, the outermost layer of the skin—the stratum corneum—loses hydration. Over time, chronic inadequate hydration can contribute to premature aging and impaired skin function,” explains Ojong. 

As the body’s largest organ, your skin goes beyond just its appearance. It acts as a protective barrier, helps regulate body temperature and plays a crucial role in maintaining fluid balance. Without adequate hydration, these vital functions become compromised, which can lead to an array of issues. Staying well-hydrated supports not only the look of your skin but also its essential role in keeping your body healthy.

Don't Miss

What Happens to Your Sleep When You Eat Chocolate Before Bed

3 Things to Do After Work to Improve Mental Health, According to Experts

What Happens to Your Skin Without Enough Water

Your Skin May Look Dull

If your skin is dehydrated, it’s often easy to notice. Common signs—dullness, uneven tone, fine lines, flakiness, rough patches and reduced skin elasticity—can look a lot like aging, says Ojong. The key difference is that when these signs stem from dehydration rather than age, they can appear seemingly overnight and improve relatively quickly once you boost your skin hydration—internally and externally.

“Well-hydrated skin cells are fuller, leading to noticeable improvements in skin texture and appearance,” says Arjun Dupati, M.D. “Even one to two days of better hydration can improve the appearance of dull or tired skin.”

Here’s the thing: Most research suggests that topical moisturizers and creams are more effective at hydrating the skin and preventing water loss, while drinking water offers more modest benefits. Still, drinking enough water helps your skin function properly and supports the delivery of nutrients to skin cells, which may contribute to a healthier appearance.

It’s important to remember that hydration isn’t a shortcut to stop the natural aging process. “Staying hydrated plumps skin a little, but it won’t reverse lines called by sun damage or collagen loss,” says Ojong.

Your Skin Barrier May Be Weakened

The skin is your body’s first line of defense against harmful pathogens, ultraviolet (UV) radiation and pollutants. Since water is essential for skin cell function, poor hydration may weaken the skin barrier, leaving your skin more vulnerable to irritation, infection and premature aging. “A skin barrier that’s repeatedly dry becomes less effective at keeping irritants and pollution out and locking the beneficial water in,” says Ojong. 

Drinking enough water is one important step in supporting a healthy skin barrier, but it’s not the only one. Using proper skin care, eating a nutrient-dense diet, exercising regularly and getting sufficient sleep all help maintain skin barrier function.

It’s also crucial to protect your skin from UV rays. “Hydration alone is not sufficient to protect against UV radiation. Be sure to use sunscreen daily,” adds Dupati.

Your Skin May Heal More Slowly

Dehydration can also affect how quickly your skin heals. When you’re not properly hydrated, cuts and scrapes may take longer to repair since optimal fluid intake is essential for tissue regeneration. Your body relies on fluids to transport oxygen and nutrients to cells and remove waste, all of which are crucial for wound healing. In fact, studies show that adequate hydration can improve treatment outcomes for conditions such as leg and diabetic foot ulcers.

You May Have Poor Temperature Regulation

Your skin plays a key role in regulating body temperature, but it can’t do its job well without enough water. “When you’re well hydrated, you can sweat efficiently and send blood to the skin’s surface to release heat. But when you’re dehydrated, sweat production drops and skin blood flow decreases,” says Ojong. This can make you more prone to overheating.

In a small 2024 study, adults who exercised in a warm environment after mild dehydration reported feeling hotter, more humid and less comfortable than when they were adequately hydrated—even though their body temperature and sweating responses were similar. While this study didn’t directly look at skin, it shows that even mild dehydration can affect how your body responds to heat and overall comfort.

How to Keep Skin Hydrated from the Inside Out

Both Dupati and Ojong agree that moisturizers are important for maintaining hydrated skin, but they can’t make up for systemic dehydration. To stay hydrated from the inside out, they recommend prioritizing unsweetened drinks like plain water, herbal tea, milk and sparkling water throughout the day. For regular coffee and tea drinkers, these beverages can also contribute to your total water intake, but shouldn’t be your main source and may have a diuretic effect in non-frequent consumers.

They also recommend spreading your fluid intake evenly throughout the day rather than chugging a bunch at once. “This will allow your body to absorb the water consistently and more efficiently,” says Dupati. 

If you’re sweating a lot—due to hot weather or intense exercise—you may want to add electrolytes to your water for better hydration, says Dupati. Don’t fall for expensive “hydrating waters” or “detox drinks” that claim to transform your skin, advises Ojong. “Fancy infusions are not better than plain water or a balanced diet rich in fruits, vegetables and healthy fats,” she says.

Foods can also contribute to hydration—around 20% of your daily needs come from water-rich foods. “Water-dense produce like cucumbers, watermelon, strawberries, citrus, bell peppers and leafy greens provide both water and skin-friendly antioxidants,” says Ojong. Fluid-based meals, such as soups, also add to total fluid intake. Ojong also recommends eating foods rich in omega-3 fatty acids, protein and vitamin C—like salmon, sardines, walnuts, chia seeds, citrus fruits, berries and bell peppers—to strengthen your skin barrier and lock in hydration.

Recipes to Try

Cucumber, Tomato & Avocado Salad with Lemon-Shallot Vinaigrette

5.0

Crispy Salmon Rice Bowl

4.8

Chicken & Bok Choy Soup with Ginger & Mushrooms

4.7

Our Expert Take

There’s no doubt about it—good hydration is essential for both skin and overall health. Drinking enough water and other fluids helps keep your skin looking healthy and functioning properly, including supporting a healthy skin barrier, aiding in wound healing and regulating body temperature. That said, hydration is not a cure-all for skin concerns. “Think of hydration as supporting skin function, not as a miracle cure. It works best alongside sun protection, a healthy diet and a consistent skin-care routine,” says Ojong. 

Ultimately, staying hydrated is one of the simplest ways to help boost the health and performance of your skin—and of your body overall.