How Much Water Do You Really Need Each Day?

Written By Nina Pliakos

This post is for educational purposes only and is not medical advice. Please consult your healthcare provider for personalized guidance.

If you’ve ever heard the advice to drink “8 glasses of water a day,” you’re not alone. But is that really how much we need and does that apply to everyone?

As a primary care provider, one of the most common and overlooked contributors to fatigue, headaches, constipation, and even dizziness is dehydration. But water needs vary depending on your age, weight, climate, and activity level.

Why Does Water Matter So Much?

Water plays a role in almost every system of the body:

  • Keeps your skin healthy and hydrated

  • Regulates body temperature

  • Cushions your joints

  • Aids digestion and prevents constipation

  • Helps flush out toxins through your kidneys and urine

  • Supports focus, mood, and energy levels

How Much Should You Drink?

There’s no “one-size-fits-all” amount of water.

That said, general recommendations are:

  • Women: About 2.7 liters (91 ounces) per day

  • Men: About 3.7 liters (125 ounces) per day

But this includes water from all sources—not just plain water. That means food, tea, coffee, and even fruits and vegetables contribute to your hydration.

Factors That Affect How Much You Need

You may need more water if-

  • You exercise or sweat heavily

  • You live in a hot or dry climate (hello, Arizona!)

  • You’re pregnant or breastfeeding

  • You’re sick with a fever, vomiting, or diarrhea

  • You eat a diet high in salt or processed food

You may need less if-

  • You have certain kidney, heart, or liver conditions (your provider will guide you)

  • You're on medications that affect fluid balance (like diuretics)

Easy Signs You’re Hydrated

Forget counting ounces every day. The best way to tell?
✔️ Your urine is light yellow to clear
✔️ You’re rarely thirsty
✔️ You feel alert and energized

What Counts as “Water”?

These things can hydrate you as well— Herbal teas, broths, sparkling water, fruits (like watermelon, oranges, cucumbers), vegetables (like lettuce, celery, zucchini)

Caffeinated drinks (like coffee) and alcohol can still contribute to your daily fluids, but they may have a mild diuretic effect—so balance them with water.

Too Much Water?

Yes—though rare, overhydration can lead to a dangerous condition called hyponatremia (low sodium levels). This usually only occurs in endurance athletes or people drinking extreme amounts in a short time. If you're healthy and drinking when you're thirsty, you're unlikely to overdo it.

Drink enough water to feel good, keep your urine pale, and stay energized—but don’t obsess over exact numbers. You can keep a reusable water bottle nearby, drink a glass with each meal or snack, pay attention to your thirst cues, and increase intake on hot and active days!

If you're feeling sluggish, constipated, or your urine is dark yellow, it might be time for a water check!

STAY HYDRATED :)

-Nina

Nina Pliakos
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