6 Surprising Signs You Need to Drink More Water

Bottoms up! Staying properly hydrated offers radiant skin, fresh breath, mental clarity and more.

Medically reviewed in August 2021

cold water bottles
1 / 8

You may think that your body will always let you know the optimal time to replenish your fluids. But the fact is, thirst isn’t a foolproof sign of dehydration. Your age, the weather and the activity you’re involved in, among other factors, can all interfere with your thirst response. 

This is important to recognize because losing just 1.5 percent of your total water weight is considered “mild dehydration” and can lead to fainting, accidents, injuries and more. So, aside from feeling thirsty, how else can you tell when it’s time to drink up? 

Samuel Nickles, MD, a surgeon at Summerville Medical Center and Palmetto Adult and Children’s Urology in Charleston, South Carolina, offers some helpful tips about dehydration and some red flags to look out for. Grab a cool glass of H2O if you experience any of these surprising signs.

woman at desk with headache
2 / 8
Brain fog and exhaustion

Not on your A-game today? Even slight dehydration could be to blame. It can reduce concentration, cause fatigue, worsen mood and lead to headaches, according to a study published in The Journal of Nutrition.

The risks of severe fluid loss are well known, but researchers were curious about the mild dehydration you might experience in daily life. How risky is it really if you skip a few glasses of water? Researchers controlled hydration levels in 25 young women at rest and during exercise. The women who were less hydrated scored lower on mood and reasoning tests. They also reported difficulties concentrating and completing their work on those days.

couple sharing food
3 / 8
Hunger you just can’t satisfy

Mild dehydration can mask itself as hunger and might make you more prone to sugar cravings. On the other hand, staying well hydrated can trick you into feeling full, says Dr. Nickles. Your satiety level, or feeling of fullness, is influenced by your stomach contents—regardless of whether you consume solids or liquids. That means drinking water could curb your appetite, he explains.

Researchers need to learn more about why hunger and thirst sometimes get confused. One explanation: Since dehydration can hurt your ability to think clearly, it could make it harder to differentiate between the two sensations.

checking bad breath
4 / 8
Bad breath

Saliva keeps your mouth naturally fresh by rinsing away odor-causing bacteria and food particles. Dehydration can allow debris to build up on mouth surfaces and contributes to foul-smelling vapors. 

Prevent bad breath by:

  • Sipping from a personal water bottle throughout the day
  • Munching on high-fiber, high-water-content fruits and vegetables like apples, pears and carrots
  • Chewing sugar-free gum between meals to stimulate saliva production
girl looking in mirror
5 / 8
Dry, flaky skin

Dehydration can prevent a layer of your skin called the stratum corneum from receiving the moisture it needs. That can lead to skin having a dull appearance, along with stretched pores, fine lines and flakiness.

Even if your skin is oily, it’s still possible to be dehydrated. In fact, dehydrated skin is prone to excess oil and breakouts, as oil glands try to make up for the lack of moisture.

Keep your skin glowing by:

  • Drinking a large glass of water instead of, or before, your morning coffee
  • Skipping nicotine, alcohol and excess caffeine
  • Avoiding long, hot showers and baths, which can wash away your natural oils and dry your skin out even further
  • Applying moisturizer as soon as you get out of the bath
An Image
6 / 8

“Dehydration may cause your blood pressure to drop, which can reduce vascular tone in your brain and may lead to headaches,” says Nickles. 

Vascular tone refers to how tight your blood vessels are. Low blood pressure means less blood and less oxygen being carried to brain cells; the vessels in your brain widen to try to increase the flow. These changes can trigger migraine headaches.

You may also experience what’s known as a dehydration headache if you’re not getting enough fluids. In addition to symptoms of dehydration like thirst and dark-colored urine, you may have a dull headache with pain that increases when you move your head. You may feel pain anywhere around the head, but not likely in the face, sinuses or back of the neck.

Remedies include avoiding alcohol and caffeine, reducing physical activity to cut down on sweating—and, not surprisingly, boosting your fluid intake.

An Image
7 / 8
Urine color

“Urine color is influenced by several factors, including hydration,” says Nickles. “Typically if your urine is a pale straw-yellow, it means you're well hydrated. If it becomes a little too yellow, it means you should drink some water.”

Here’s what your pee color could indicate:

  • Clear or pale straw-yellow: You’re a hydration all-star. Keep up the good work. 
  • Honey or yellow: You may be mildly dehydrated. Take some sips.
  • Dark yellow, amber or orange (along with less frequent urination): You’re more severely dehydrated, or you could have a condition that requires medical attention. Drink plenty of water and call your healthcare provider (HCP) if the dark color persists. 
woman drinking water
8 / 8
How much water do you need in a day?

The common advice to aim for eight glasses a day isn’t actually based on hard science. The truth is, the amount of water you need varies depending on your age, health, activity level, sex and other factors. 

Roughly speaking, though, if you’re a healthy adult male living in a temperate climate, 3 liters of water, or 13 cups a day, should keep you hydrated. For healthy adult women, 2.2 liters, or 9 cups should do the trick. 

Remember that all fluid you take in counts toward the daily total, whether that comes from water, sports drinks or tea. Food also provides about 20 percent of your total water requirement.

And it is possible to have too much of a good thing, even when it comes to hydration. If you have certain health conditions—such as heart disease or thyroid, adrenal, kidney or liver disease—ask your HCP about the right amount of water for you.

More On

How should I fuel for a workout?


How should I fuel for a workout?
Hi I'm Dr. Joy Dubost, registered Dietitian and Spokesperson at American Dietetics Association. And I'm here to talk to you about how to properly fuel...
Good News for Chocolate Lovers


Good News for Chocolate Lovers
I have an ongoing love affair with chocolate. Well, it’s actually more of a love/hate relationship. Once I start eating chocolate, I just can’t stop....
6 Creative Ways to Enjoy Sweet Potatoes


6 Creative Ways to Enjoy Sweet Potatoes
From pizza to smoothies, it’s easy to add this versatile veggie to your diet.
Eating fruit can help you stay hydrated


Eating fruit can help you stay hydrated
Sweet potato hash


Sweet potato hash