10 signs of dehydration you need to know

Studies show that more than 75% of Americans suffer from chronic dehydration. If left untreated, dehydration can lead to significant health problems, particularly for children or older adults.  

Monitoring for dehydration symptoms is the key to proper dehydration treatment and can help prevent more serious, life-threatening conditions. If dehydration becomes more severe, it can lead to signs of mental and physical decline that will need immediate medical action for reversal. 

1. Not urinating or very dark urine 

An easy way to test and see if you’re dehydrated is by checking the color of your urine. Normal urine should be pale yellow, like lemonade. If your urine is a darker color, similar to apple juice, this could be a sign of moderate to severe dehydration.  

If you’re not urinating, you’re most likely severely dehydrated. This requires immediate medical attention. 

What to do: If you find your urine is dark yellow, start drinking more water immediately. It’s best to take frequent small sips of water that your body can adequately absorb.  

If you feel you’re not getting enough fluids regularly, consider taking a large water bottle to drink throughout the day — at work, in the car and on the go. 

2. Dry skin that doesn’t bounce back when pinched 

Lack of skin elasticity is another sign of dehydration.  

Try this test: Pinch the skin on the top of your hand and see what happens. If it moves back slowly, this is an indication that you’re moderately dehydrated. If the skin seems to stick together (i.e., it “tents”), this is a sign of severe dehydration. 

What to do: Just like with darker urine, you should increase your water intake and drink fluids if you’re experiencing mild to moderate dehydration. A glass of water is typically a good “go-to”. 

If you are severely dehydrated and your skin tents, you may have to visit a healthcare provider who can help treat dehydration. 

3. Rapid heartbeat and breathing 

It’s natural to have an increased heart rate and rapid breathing while exercising. But if your symptoms don’t go away once you’ve cooled down or haven’t been working out, it could be a sign of severe dehydration. That’s because depleted blood volume can affect the heart’s ability to pump blood. 

What to do: If you are experiencing these symptoms, you should visit a healthcare provider to assess for dehydration. You may need IV hydration to reverse severe dehydration that is impacting your breathing. IV hydration provides fluid and has salt and sugar like sodium chloride and potassium to aid in quick rehydration. 

4. Dizziness or lightheadedness 

Did you know that your brain is approximately 75% water? That’s why drinking water and eating water-filled foods can help your brain work better.  

On the flip side, if you don’t get enough fluids, it can negatively affect your brain function. For example, if you are experiencing dizziness or lightheadedness or feel as if you may pass out, this may mean you are severely dehydrated.  

What to do: Don’t take symptoms like these lightly. Properly rehydrate by slowing drinking water.  However, if you’re experiencing dehydration dizziness or lightheadedness, you should go to the emergency room as soon as possible to be checked out by a healthcare provider. 

Consider eating more fruits and vegetables with high water content to prevent dehydration.  These include cucumbers, watermelon, tomatoes, strawberries, apples and grapes. This will help replenish your body with minerals and electrolytes. 

5. Unconsciousness 

Unconsciousness from dehydration can result from low blood pressure or dizziness. When accompanied by other dehydration signs, this could indicate a severe fluid loss.  

What to do: Call 911 immediately if you’re around someone who passes out or you’re alone and feel like you may pass out. This requires transportation to the emergency room right away for dehydration treatment.  

Like with other severe signs of dehydration, you or the person affected will most likely receive rehydration therapy.  

6. Fatigue 

Another classic sign of dehydration is fatigue. Studies have shown those who sleep less tend to be more dehydrated and those who were well hydrated slept longer on average. 

What to do: If you feel frequently tired shortly into your workouts or regularly fatigued, it’s likely a good time to evaluate your water intake. Call your healthcare provider or local urgent care if you experience extreme fatigue that affects your everyday life. 

9. Sunken eyes or dry eyes 

While perhaps not as obvious, having dry or sunken eyes is also a classic symptom of dehydration. This is because less fluid and tears are circulating, leading to dryness in the eyes. 

In these cases,  your eyes can burn. It may even feel like you have sand in your eyes, or they may become more sensitive to light.  

What to do: If any of these symptoms occur, drinking water may help. 

10. White tongue 

Dehydration can also cause a physical symptom called the white tongue. This appears as a white coating on the tongue's surface caused by debris, bacteria and dead cells that become lodged and inflamed. This can occur for many reasons, but the primary causes are dehydration and dry mouth. 

What to do: While a white tongue is generally harmless, it can be an underlying sign that you’re dehydrated. Drink plenty of water and brush your tongue gently with a toothbrush. If it doesn’t go away in a few weeks, it’s a good idea to call a healthcare provider. 

Causes of dehydration 

There are several possible causes of dehydration, typically either due to not drinking enough water or from losing bodily fluids: 

  • Inadequate fluid intake: If you’re not drinking enough water or water-containing foods like fruits and vegetables, it’s easier to become dehydrated. 
  • Diarrhea and vomiting: These symptoms cause fluid loss, which can result in dehydration. 
  • Excessive sweating: This can result from strenuous or endurance physical activity or exposure to hot weather conditions. 
  • Increased urination: This can occur if you have diabetes or certain medications that can cause you to urinate more and lose fluid, such as diuretics or blood pressure medications. Also be mindful, that coffee/caffeine and alcohol can increase urination. 
  • Fever: Having a fever alone dehydrates you. That’s because an increase in body temperature increases your metabolism and breathing rate, leading you to breathe out more moisture. Fever can cause dehydration, especially in kids, due to increased insensible water losses. Dehydration doesn't cause fever though.   
  • Hot weather: Overheating due to hot temperatures can also cause dehydration. 

Tips to prevent dehydration 

These tips can help you prevent dehydration, which is easier than treating it after it has already happened.  

  • Keep a water bottle by your side and in your line of sight.  
  • Add natural ingredients to your water, like fresh strawberries, cucumbers and orange or lemon slices. The flavor may encourage you to drink more water.  
  • Eat more water-filled fruit and vegetables. In fact, cantaloupe, watermelon, leafy greens and tomatoes all contain 90% water. 
  • Drink electrolytes or coconut water after a workout. 
  • Avoid alcohol consumption if you’re already feeling dehydrated, as this increases your fluid loss. 

FAQs about dehydration 

Here are some common questions about dehydration. 

Does dehydration cause high blood pressure? 

Yes, dehydration can cause your blood pressure to fluctuate, leading to blood pressure that is too high or too low.  

What happens if you drink too much water? 

Drinking too much water can dilute essential electrolytes, swelling the body’s cells and disrupting brain function. Common signs of too much water can be nausea, vomiting, confusion and disorientation. The kidneys are designed to urinate out the excess, so unless someone is purposefully drinking excessively, this isn't a practical concern  

What is the fastest way to cure dehydration? 

The fastest way to cure dehydration is to drink fluids, particularly those that contain electrolytes, such as sports drinks or oral rehydration solutions. People unable to drink properly due to medical conditions may require IV hydration for faster results. 

What does a dehydration headache feel like? 

Pain from a dehydration headache can vary. With mild dehydration, it can feel like a dull throbbing but can be sharp or pounding as dehydration worsens. 

Visit an urgent care for dehydration symptoms 

When you’re severely dehydrated, your gut reaction might be to chug fluids or water-filled foods into the body as quickly as possible. However, you don’t want to overdo it. It’s possible to drink too much water, resulting in a condition called hyponatremia. This is when sodium and electrolytes in the blood are so low that they can be life-threatening. As mentioned above, this is challenging to do and usually requires kidney or other medical problems. 

Dehydration can be dangerous if left untreated, particularly for children or older adults. Understanding your fluid needs based on age, medical status and lifestyle can help you keep your hydration status balanced. 

If you need help assessing the warning signs of dehydration and treating it, visit the experts at our urgent care centers through our healthcare provider partners. You can walk in without an appointment or save your spot online. We’ll have you back to feeling better in no time. 


  1. https://www.ncbi.nlm.nih.gov/books/NBK555956/ 
  2. https://my.clevelandclinic.org/health/treatments/9013-dehydration 
  3. https://www.webmd.com/beauty/ss/slideshow-signs-skin-hydration 
  4. https://www.mayoclinic.org/diseases-conditions/dehydration/symptoms-causes/syc-20354086 
  5. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6068860/ 
  6. https://pubmed.ncbi.nlm.nih.gov/30395316/ 
  7. https://pubmed.ncbi.nlm.nih.gov/25950246/ 
  8. https://www.mayoclinic.org/symptoms/white-tongue/basics/causes/sym-20050676 
  9. https://health.clevelandclinic.org/dehydration-and-blood-pressure/ 

Written by Sarah Thebarge, Physician Assistant