You’re Not Just Tired—Your Body Might Be Crying for Water

You wake up exhausted, even after a full night’s sleep. Maybe you didn’t sleep well again. You push through the morning, relying on coffee to keep going. By mid-afternoon, the brain fog sets in, and you feel drained, irritable, and overwhelmed.

You tell yourself it’s just the stress of juggling everything—work, kids, life. Maybe you blame your hormones or assume you need more rest.

But does dehydration make you tired? More than you might think.

Dr. F. Batmanghelidj, in Your Body’s Many Cries for Water, explains that many common symptoms—fatigue, headaches, brain fog, anxiety, and even feeling overwhelmed—can actually be signs of chronic dehydration. And by the time you feel thirsty, your body is already struggling.

Let’s explore how not drinking enough water could be draining your energy—and more importantly, what to do about it.

(If you want to dive deeper into this fascinating topic, I highly recommend reading Dr. Batmanghelidj’s book, Your Body’s Many Cries for Water, which explores the science behind hydration and health in much more detail.)

1. Does Dehydration Make You Tired? Why Your Energy Depends on Water (Not Just Sleep)

Your body is 60-70% water. Every single function—cell repair, digestion, blood circulation, and brain function—relies on proper hydration.

Here’s what happens when you don’t drink enough:

• Your brain slows down. Since the brain is about 75% water, even mild dehydration can cause fatigue, brain fog, and difficulty concentrating.

• Your cells produce less energy. Water is essential for converting food into usable energy (ATP). Without enough water, your cells can’t generate energy efficiently, leaving you feeling sluggish.

• Your heart has to work harder. Dehydration thickens the blood, making it more difficult for the heart to circulate oxygen and nutrients—resulting in low energy and physical exhaustion.

And the worst part? When you’re dehydrated, your body conserves water by reducing circulation to non-essential functions—like digestion and deep cellular repair—which means you don’t recover properly overnight. The result? Even more exhaustion the next day.

If you’ve ever wondered, "can dehydration cause fatigue?"—the answer is yes. Dehydration not only affects energy production but also makes it harder for your body to function optimally.

2. The Stress-Dehydration Cycle: Why You’re Trapped in a Loop

When you’re stressed, your body releases cortisol, the primary stress hormone. What most people don’t realise is that dehydration increases cortisol levels, making you feel even more anxious, irritable, and on edge.

• Less water = more stress. When your body lacks water, it interprets this as a state of crisis and triggers a stress response.

• More stress = less water. At the same time, high cortisol levels reduce your body’s ability to retain water, causing further dehydration through urine and sweat.

The result? You feel mentally foggy, emotionally drained, and physically exhausted—but instead of reaching for water, you go for coffee or sugary snacks, which only worsen dehydration.

I previously wrote about how staying hydrated can re-energise your day and help combat daily exhaustion. If you missed that post, you can read it here: [insert link]. But today, let’s take it further and talk about how dehydration might be slowing your metabolism and increasing stress.

3. Can Dehydration Cause Fatigue? Watch for These Signs

Most mums don’t realise they’re dehydrated because they don’t always feel thirsty. Instead, the body may send different warning signs:

• Morning grogginess (even after a full night’s sleep)

• Low energy and mid-afternoon crashes

• Cravings for sugar, caffeine, or salty foods (your body seeking hydration through food)

• Headaches or tension in the neck and shoulders

• Irritability, brain fog, or feeling emotionally overwhelmed

• Dry lips, dry mouth, or dark urine

Try This Simple Dehydration Test

If you’re unsure whether you’re dehydrated, try the skin pinch test:

1. Pinch the skin on the back of your hand and hold it for a second.

2. Release and watch how quickly it returns to normal.

• If your skin bounces back immediately, you’re likely well-hydrated.

• If it takes a few seconds to return to normal, this is a sign of dehydration.

This quick test can help you identify whether your body is in need of water before symptoms become severe.

4. Why Hydration is Key for Metabolism, Weight Loss, and Reducing Bloating

If you’ve been struggling with weight gain, bloating, or cravings, dehydration could be a hidden culprit. Here’s why:

• Dehydration slows metabolism. Your body needs water for every metabolic process, including fat breakdown (lipolysis).

• Increases fat storage. Dehydration triggers cortisol release, which is linked to increased belly fat storage.

• Confused hunger signals. Your brain often mistakes thirst for hunger, leading to unnecessary snacking.

• Water retention & bloating. Dehydration causes fluid retention, making you feel puffy and swollen.

Bottom line: Drinking enough water boosts metabolism, curbs cravings, regulates stress hormones, and prevents bloating.

5. How Much Water Do You Actually Need?

Forget the “8 glasses a day” rule—hydration isn’t one-size-fits-all. Dr. Batmanghelidj recommends drinking at least 30-40 ml of water per kilogram of body weight per day.

A simple way to check? Multiply your weight (in kg) by 0.03-0.04.

• Example: If you weigh 70 kg, aim for 2.1 to 2.8 litres of water per day.

6. Small Hydration Tweaks That Will Change Your Energy

• Start your day with water before coffee.

• Reduce dehydrating drinks. For every cup of coffee, drink an extra glass of water to compensate.

• Make hydration effortless. Keep a water bottle with you and add lemon, cucumber, or sea salt to make it more enjoyable.

• Hydrate before bed. Many mums wake up exhausted because they go to bed dehydrated.

Listen to Your Body’s Cries for Water

Your exhaustion isn’t just about being busy. It’s not just stress. Sometimes, the simplest solutions—like drinking more water—can make the biggest difference.

So before reaching for another coffee, pause. Drink a glass of water, wait 20 minutes, and notice how you feel.

You might just realise your body wasn’t tired—it was thirsty.

With love,

Karo