Better Me

How to Prevent Dehydration When You Have Diarrhea or Vomiting

Did the stomach bug hit your home? Vomiting (throwing up) and diarrhea can take a lot out of you – literally. When your child, older parent or even you are sick, it’s easy to lose fluids fast. And when your body loses more fluids than it takes in, dehydration can happen. 

Dehydration isn’t just about feeling thirsty. It can make someone feel weak, dizzy and tired – and in serious cases, it can lead to a trip to urgent care or the ER. That’s why it’s important to start replacing lost fluids early, even before symptoms of dehydration show up.

We spoke with Samia Kadri, a family nurse practitioner with Banner Urgent Care, about the signs of dehydration and the best ways to keep yourself and your loved ones hydrated at home.

Why does dehydration happen so quickly when you are sick?

Dehydration happens when your body doesn’t have enough fluids and electrolytes, minerals important in keeping your body balanced.

“When you have excessive diarrhea, your body loses vital electrolytes like potassium, sodium and bicarbonate,” Kadri said. “When you throw up, it causes a loss of fluids, stomach contents and electrolytes like potassium as well.”

Without enough fluids, your heart, brain and other organs can suffer.

“We continually need water to support biological functions and health,” Kadri said. “Staying hydrated helps us move nutrients and waste, maintain blood pressure, digest food and regulate body temperature. If fluids aren’t replaced quickly, symptoms can get worse – and fast.”

What are the signs of dehydration?

It’s important to recognize the signs early. Watch for these symptoms in children, adults and older adults (elderly).

In babies and young children:

  • Fewer than six wet diapers in 24 hours
  • No tears when crying
  • Dry mouth or tongue
  • Sunken soft spot (fontanelle) on the head
  • Unusual fussiness or drowsiness
  • Warm or feverish

Learn more about preventing dehydration in infants and children.

In teens and adults:

  • Dry mouth and cracked lips
  • Extreme thirst
  • Dark yellow urine (pee) or little to no urine
  • Dizziness or lightheadedness
  • Weakness, tiredness or confusion

In elderly or older adults:

  • Dry, sticky or tacky-like lips and mouth
  • Extreme thirst
  • Dizziness or confusion
  • Dark-colored urine or little to no urine
  • Low blood pressure
  • Difficulty standing or walking
  • Fainting
  • Trouble waking up

Check out these tips about preventing dehydration in senior populations.

If these symptoms worsen or someone becomes difficult to wake, seek medical care immediately (see below).

6 ways to avoid dehydration during diarrhea or vomiting

Kadri shared the most effective ways to help replace lost fluids and rehydrate:

1. Start with small sips

“Anyone feeling thirsty should start with small sips of water,” Kadri said. “Gulping a full glass may cause more vomiting.”

Here’s how much to give:

  • Children: Give two to three teaspoons of fluid every five minutes for three to four hours.
  • Teens and adults (over 65 pounds/30 kilograms): Aim to drink two to four liters (about eight to 16 cups) over three to four hours.

Start slow and increase the amount as your body can handle it.

2. Choose the right fluids

Stick with drinks that help your body absorb water and electrolytes.

Try these options:

  • Water
  • Oral rehydration solutions (see #3)
  • Clear broth (chicken, beef or vegetable)
  • Sugar-free electrolyte replacement powder or drink
  • Ice chips or electrolyte ice pops

Avoid these:

  • Caffeine (coffee, tea or energy drinks)
  • Alcohol
  • Coconut water
  • Sugary drinks (soda, fruit punch or Gatorade)

“Sugary juices, sports drinks like Gatorade and soda aren’t recommended because they don’t have the right balance of sugar and salt your body needs,” Kadri said. “Even coconut water isn’t ideal as it may not provide enough sodium and may contain too much potassium.”

3. Use oral rehydration solutions (ORS)

“ORS products contain the right mix of sugar, salt and water to help your body absorb fluids better,” Kadri said.

These are available in most drugstores. Look for:

  • Pedialyte (not always recommended for under age 1; check with your provider)
  • DripDrop
  • Enfalyte
  • Store-brand rehydration drinks

You can also make your own by mixing four cups of clean water with six teaspoons of sugar and a half teaspoon of salt.

Give small sips often using a spoon, cup or syringe, especially for children.

4. Eat bland, easy foods when ready

If vomiting has stopped, you can try small meals to support recovery.

Choose BRAT foods:

  • Bananas
  • Rice
  • Applesauce
  • Toast

Other good choices include:

  • Cooked carrots or potatoes
  • Plain crackers
  • Steamed chicken

Avoid dairy, fried foods and spicy meals until you feel better.

5. Check before taking medication

Talk to your health care provider or a Banner Health specialist before using anti-diarrhea or anti-nausea medications, especially for:

  • Children
  • Older adults
  • People who are pregnant
  • Anyone with ongoing health conditions

These medications aren’t always safe, and stopping diarrhea too soon can sometimes make things worse.

6. Know when to seek medical attention

Sometimes, vomiting or diarrhea can signal something more serious.

Call your doctor or go to urgent care if:

  • Vomiting or diarrhea lasts more than two days
  • There’s blood in vomit or poop
  • Your child has a fever over 100.4°F (under 3 months) or over 102°F (older)
  • Signs of dehydration are getting worse
  • You’re unable to keep fluids down for more than 12 hours

Go to the emergency room if:

  • You become very weak, confused or hard to wake
  • Your child has a dry mouth, sunken eyes or fewer than three wet diapers in a day
  • There’s no urine for eight hours or more

Takeaway

Dehydration can happen quickly when you are throwing up or have diarrhea. Remember to start with small sips often, use oral rehydration solutions, avoid sugary and caffeinated drinks and eat bland foods when ready.

If you’re unsure what to do or symptoms worsen, trust your gut and call your provider. You know your family best.

Banner Health is here to help. Find a Banner Health specialist or urgent care location near you.

Related articles:

Wellness Urgent Care Infectious Disease Gastroenterology