How Much Water Should You Drink a Day? Plus Signs You're Hydrated

Most people assume that eight glasses of water is enough for optimal health and digestion, and that's a great rule of thumb—but the truth is there isn't one standard amount of water that applies to everyone. The amount of water you should drink daily is impacted by a multitude of both personal and external factors. We caught up with health experts to better understand how to know how much water is right for you. Here's what they had to say.

Daily Recommended Water Intake

While studies have produced varying recommendations over the years, when it comes to meeting the hydration levels of the average healthy adult, most health experts do generally recommend drinking around two liters a day, or about eight 8-ounce glasses of water.

"This amount can include water, other liquid beverages, and water-dense foods," says nutritionist Serena Poon. "With my clients, I recommended a goal of about 2 liters of water per day to maintain healthy levels of hydration." Using a water filter pitcher is one way to keep track of your daily water intake.

However, you might be drinking the recommended amount and still find yourself feeling parched. According to Sinatra, there are several additional factors that help determine how much water you should drink daily, including:

• Age
• Activity level
• Diet
• Climate
• Certain medications
  

What Happens When You Don't Drink Enough

Not drinking enough water can take a negative toll on your energy levels and brain function. When you don't drink enough water, you become dehydrated, which can lead to a whole host of issues that impact your health. Dehydration can cause fatigue, reduce alertness, and make it more difficult to concentrate, all of which can impair your mood. Decreased alertness and difficulty focusing can also impact your memory and overall cognitive performance.

Therefore, staying adequately hydrated is important. If you have plenty of energy to go about your day and think straight, that's a good sign. But if you're constantly fatigued, irritable, and/or headachy, note that dehydration could be a contributing factor (along with good sleep, regular exercise, and a balanced diet, of course). It might be time to drink some water.

What Happens When You Drink Too Much

It's possible to drink too much water. While staying hydrated is important, overhydration can cause electrolyte imbalances, water intoxication, and hyponatremia (low blood sodium levels).

Hyponatremia can cause symptoms like nausea, headache, confusion, and, in severe cases, seizures. Rarely, it can even be life-threatening. Therefore, it's important to listen to your body and make sure that you're getting enough water but not overdoing it.

Why You Need to Drink Water Daily

Drinking water is arguably the single most important thing you can do for your body. However, it's smart to listen to your body to figure out your ideal water intake because drinking too much or too little can affect everything from your metabolism to your mood. Here are just a few of the things the right amount of H2O does for the body.

Helps Organ Function

"Water is to the body what gasoline is to a car,” says physician Benedict Ifedi, MD, who is also board-certified in sports medicine. Every one of our cells, tissues, and organs—including our heart, kidneys, and liver—requires water to function.

Lubricates Joints and Tissues

"Water is essential for the lubrication of our joints as well as our digestive tract and mucous membranes," explains dietitian Hillary Ake, RD. Without water, you might notice achier or stiffer joints, as well as limited mobility.

Regulates Body Temperature

“During exercise or any activity in which a person gets warm, sweat is used as a method of thermoregulation—meaning that your body releases heat at the skin’s surface and the evaporation of sweat cools the skin,” Ake explains. Your body needs enough fluids to sweat fluids—and when you do sweat those fluids, you need to drink more water to replenish.

Supports Gut Health

Water transports nutrients through our bodies and helps with digestion. There's also evidence that it's important for shaping our biome, the community of bacteria and other microorganisms in our gut.

Improves Cognition and Mood

Water helps our brain cells communicate with each other, transports nutrients, and carries away toxins. According to several studies, participants who drank water performed better on memory-related tests (for instance, recalling a list of objects) than those who didn't drink.

Evidence has also suggested that water consumption is associated with decreased depression and anxiety in adults. In addition to boosting our energy levels and supporting our physical well-being, water also transports tryptophan, an amino acid that our body needs to produce the feel-good neurotransmitter serotonin. It may also lower levels of the stress hormone cortisol.

Wards Off Diseases

Research finds that people who stay sufficiently hydrated appear to live longer and develop fewer chronic illnesses than those who don’t get enough fluids. This includes heart failure, stroke, lung disease, diabetes, and dementia.

Enhances Skin

Bonus round: While drinking water might not moisturize your skin, it can help maintain skin elasticity, which is a good indicator of your overall hydration level (more on this later). Your skin needs water to keep bacteria (and breakouts) at bay, reduce fine lines and wrinkles, and maintain that healthy glow—and you can get it from both topical products, as well as from drinking water.

How to Tell if You're Drinking Enough Water Every Day

If you're not quite sure whether or not you're drinking enough water every day, there are some tell-tale signs that you are or aren't. Here are some simple ways to determine whether or not your body needs more water.

Thirst Levels

While you don't necessarily have to pound water all day long, if you often feel thirsty, then guess what? You may be dehydrated. Ideally, you want to keep your water intake steady, so you're drinking as soon as you feel the first signs of thirst or, even better, before.

Urine Color and Frequency

Before you begin to count glasses, liters, or ounces, you might want to start by looking at your urine. "A great way to measure if you're getting enough water is your urine color and frequency," Sinatra says.

"Urinating every 90 minutes to two hours is normal. If your urine is a dark amber color and you're only urinating every six hours or longer, it's likely you aren't hydrated enough. If your frequency is every 30 minutes and your urine is completely clear, you may be getting too much water, and it's likely going right through your body instead of benefiting you."

Skin Elasticity

Another way to get an idea of your hydration level is to check your skin turgor, which is your skin's elasticity. "Pinch the skin on the back of your hand for a few seconds and then release," Sinatra says. "If your skin turgor snaps back quickly into place, you're probably well hydrated. If it takes time to return to its normal position, you may be dehydrated."

Said another way: One of the benefits of drinking water is a tighter, more glowing complexion. Other symptoms of dehydration include dizziness, brain fog, and fatigue, notes Sinatra.

Delicious Ways to Drink (and Eat) More Water

If you're having trouble drinking enough water, there are several ways to boost your intake beyond plain old water. You can try infusing water with fruit, adding frozen fruit (instead of ice cubes) to your water, or opt for seltzer water with a healthy boost (no-sugar-added varieties are best). You can also focus on consuming foods with high water content. Many fruits and vegetables are water-dense, making them an excellent source of hydration.

Hydrating Fruits

Poon recommends these fruits with a high water content to help you stay hydrated:

• Strawberries (91% water content)
• Watermelon (92% water content)
• Cantaloupe (90% water content)
• Grapefruit (91% water content)
• Peach (88% water content)
• Pineapple (87% water content)
• Oranges (87% water content)
• Coconut water (95% water content)
• Raspberries (86% water content)

Hydrating Vegetables

Water-rich veggies are another simple, accessible way to add more water (and electrolytes) to your diet. Some seasonal and year-round options include:

• Cucumber (95% water content)
• Zucchini (95% water content)
• Tomatoes (95% water content)
• Cauliflower (92% water content)
• Cabbage (92% water content)
• Iceberg lettuce (96% water content)
• Celery (95% water content)
• Green peppers (94% water content)
• Romaine (95% water content)
• Spinach (92% water content)

Another great way to eat your way to better hydration is with soup. "Heat up a nice chicken or bone broth and throw in some potassium-rich foods like celery, carrots, or potatoes," Sinatra says. "Keep the salt low, but a little sodium is actually good for your hydration."

Stews, chilis, smoothies, popsicles, slushies, and tea are also excellent, hydrating choices, according to Leslie J. Bonci, MPH, RD, CSSD, LDN. But make sure to stick with water-rich ingredients like those mentioned above and avoid too much added salt or sugar.

Foods and Drinks to Avoid If You're Dehydrated

All of our experts agree that it's important for hydration to stay away from processed foods as they not only contain little water. These foods often contain elevated amounts of sodium (even sweet treats), which will hinder your hydrating efforts. The same goes for coffee.

"Coffee acts as a diuretic and can dehydrate you," Sinatra says. "I tell my patients that for every cup of coffee you drink, you should follow it with a cup of water." Ditto for alcohol, which is also extremely dehydrating (hence tomorrow's headache, sluggishness, and dull complexion). Alternating between water and alcoholic drinks—ending with water—is one of the best ways to prevent a hangover.