10 Signs You’re Dehydrated (And What to Do About It)

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Dehydration happens when your body loses more fluids than it takes in. It’s especially common during hot summer months, after exercise, during illness or simply from not drinking enough water. Even mild dehydration can have wide-ranging effects — so recognizing the early warning signs is essential to staying healthy and safe.

Here are 10 common signs of dehydration and what to do if you spot them:

1. Thirst

Seems obvious, right? But by the time you feel thirsty, you may already be mildly dehydrated. Thirst is your body’s way of signaling a fluid deficit, so respond early and often — don’t wait until your mouth feels dry.

2. Dark Yellow Urine

The color of your urine is a good hydration barometer. Light straw or pale yellow? You’re likely well hydrated. If it’s darker — think apple juice or darker — you probably need to drink more water.

3. Fatigue

If you’re dragging through your day, it might not be just lack of sleep. Dehydration reduces blood volume, which can lead to sluggish circulation and tiredness. Rehydrating can quickly restore energy.

4. Dizziness or Lightheadedness

When fluid levels drop, blood pressure can dip — causing dizziness or that head rush when you stand up. In hot environments or after exercise, this can be a red flag.

5. Dry Skin and Lips

Your skin loses moisture when you’re dehydrated, especially in the heat. Chapped lips, dry patches or flushed skin may all be signs that your hydration levels are off.

6. Headaches

Lack of water can reduce the cushioning in your brain, literally shrinking it slightly and pulling away from the skull. The result? A dehydration headache that feels similar to a tension or migraine headache.

7. Muscle Cramps

Dehydration can mess with your electrolyte balance — especially sodium and potassium — which affects muscle function. If you’re cramping up during or after a workout, hydration may be the missing link.

8. Bad Breath

Saliva helps keep bacteria in check. When you’re dehydrated and your mouth is dry, odor-causing bacteria multiply, resulting in bad breath.

9. Brain Fog

Your brain is about 73% water, and when it’s dehydrated, mental clarity suffers. Trouble concentrating, sluggish thinking or irritability can all be symptoms of dehydration.

10. Rapid Heartbeat

Dehydration causes your heart to work harder to pump blood, which can increase heart rate and make you feel more anxious or “off.” This is especially common during exertion or heat exposure.

What to Do About It:

• Drink water regularly throughout the day — not just when you’re thirsty. Set reminders if needed.
• Eat water-rich foods like cucumbers, watermelon, oranges and strawberries.
• Replenish electrolytes after intense workouts or sweating with a balanced electrolyte drink (look for options low in sugar).
• Avoid excessive alcohol and caffeine, which can dehydrate you further.
• Monitor your environment. Hot, humid or dry conditions all increase water loss, even when you’re not sweating.

When to Seek Help:

Severe dehydration can lead to confusion, fainting, rapid heartbeat or no urine output. If symptoms are extreme, seek medical attention immediately.

Dehydration can sneak up quickly, especially in summer. Know the signs, hydrate regularly, and listen to your body to stay sharp, healthy and safe all season long.