Fluids and hydration
19 Jul

Fluids and Hydration – We all need water to survive. Water is essential for the functioning of our bodies. It helps our blood circulate, helps us digest food, and removes waste from our bodies. It keeps our bones and joints healthy and also improves alertness, memory, and mood.


Fluid intake increases as we grow and age. We also need more fluids when we are active, have a fever or are in warmer weather. How much liquid do children need? Babies under 6 months get all the fluids they need from breast milk or formula. Most babies drink between 28 and 36 ounces of breast milk or formula per day. Between 6 and 9 months, a baby can drink up to 4 ounces of water per day in addition to formula or breast milk. This increases to 8 ounces between 9 and 12 months. Toddlers need 4 cups of fluids daily, school children 5 cups, and older children 7-8 cups of fluids daily. If a child plays or participates in a sport, they may need an additional 3-8 ounces of fluids for every 20 minutes of vigorous exercise. If you exercise intensely for more than an hour, an electrolyte drink or supplement may be necessary to ensure adequate hydration.


Water is a healthy and easy way to stay hydrated, but we also get it from fruit, milk, juices, and other beverages. Water or milk should be the main liquids that children consume. We do not recommend juices for children under 1-year-old. After the age of one year, we recommend limiting the juice to less than 4 ounces per day and if possible, we recommend avoiding daily juice consumption if possible. Juices often have too much sugar and not enough nutrients. Fresh fruit, which provides fluid, vitamins and minerals, and fiber, is preferred over fruit juices. Sodas and other sugary drinks should be served infrequently.

Twenty percent of fluid requirements are actually met by food! Fruits and vegetables contain a lot of water. Some are more than 90% water!

Watermelon, honeydew melon, strawberries, blueberries, grapefruit, cucumbers, zucchini, iceberg lettuce, tomatoes, and celery have high water content. Other foods are high in water, like yogurt (85% water) and ice cream (64% water)! What if your kid doesn’t like water? Make your water fun! You can add ice cubes in fun shapes or cut fruit. If necessary, add some juice for taste. Funny straws and cups can help kids be more interested in water. interesting and fun for kids, like popsicles with water and fruits. Smoothies can count as a source of hydration and are a great way to sneak in some fruit and veg!

Fluids and Hydration

Young children are more at risk of becoming dehydrated. They have smaller bodies that are less efficient at conserving water. This is particularly true if your child has a fever, is vomiting, or has diarrhea. And when they have all 3 symptoms at the same time, they are at significant risk of dehydration and water loss. 

When a child loses water and doesn’t maintain hydration, they also lose electrolytes including sodium, potassium, and chloride. These are essential for the body to conduct nerve impulses, contract muscles including the heart, and regulate the body’s fluid balance.

Signs of Dehydration:

A child with mild dehydration may have the following symptoms:
Urinating less frequently
Darker colored urine
Playing less
Parched or dry mouth
Fewer tears
Sunken soft spot

A child with moderate or severe dehydration may have the above symptoms as well as:

  • Severe fussiness or irritability
  • Sleepy or listless
  • Sunken eyes
  • Flushed skin 
  • Cool/discoloured hands and feet
  • Wrinkly skin
  • Decreased or no urination
  • Light-headedness
  • Cramping
  • Rapid pulse
  • Feels very hot or very cold
  • No tears when crying

Fluids and Hydration
When a child is sick, they need lots of fluids. But how much fluid do they need in 24 hours to maintain hydration and minimize the risk of dehydration?
WeightMinimumWith Diarrhoea
Under 10lbs10 ounces or 1.25 cups (300 ml)16 ounces or 2 cups (480 ml)
Under 20 lbs15 ounces or about 2 cups (450 ml)23 ounces or about 3 cups (690 ml)
Under 25 lbs25 ounces or about 3 cups (750 ml)40 ounces or 5 cups (1.2 L)
Under 30 lbs28 ounces or 3.5 cups (840 ml)44 ounces or 5.5 cups (1.32 L)
Under 35 lbs32 ounces or 4 cups (960 ml)51 ounces or about 6 cups (1.53 L)
40lbs and over38 ounces or 4.5 cups (1.14L)61 ounces or about 7 cups (1.83 L)

When your child is sick, has a fever, or has diarrhea, encourage them to take small, frequent amounts of fluid or food. Small frequent fluid intake helps to ensure hydration and encouraging smaller amounts can be more successful and less overwhelming for children. 

You can provide a variety of types of fluids, fruits, yogurt, smoothies, applesauce, juices, ice chips, popsicles, and soups to older children. A baby should be offered formula or breast milk if under 6 months of age, or over 6 months of age, hydrating fruits and veggies can also be offered.

If your child is unwilling or unable to eat during illness, water cannot be the only fluid offered. You also need to provide fluids with electrolytes and some calories/nutrition.

Some suggestions of things to offer include: 

  • Popsicles
  • Commercial rehydration solutions (these help with sodium and potassium)
  • Sports Drinks
  • Diluted fruit juice (straight juice can increase diarrhea)
  • Soup broth, bone broth, or stock
If your toddler or older child is vomiting, they may be thirsty but their stomach will be very sensitive to large sips or gulps of fluid. Slow rehydration works best. Start with 1 teaspoon (1 teaspoon is 5 ml of fluid) of water or rehydration solution every 5 minutes and increase the amount every 20-30 minutes as follows:
  • 0 to 20 or 30 minutes: 1 tsp or 5 ml every 5 minutes
  • 20-30 minutes to 40-60 minutes: 2 tsp or 10 ml every 5 minutes
  • 40-60 minutes to 80-90 minutes: 3 tsp or 15 ml every 5 minutes
  • Over 80-90 minutes: 4 tsp or 20 ml every 5 minutes

If your child starts vomiting at larger amounts, return to the largest amount tolerated or begin back at 5 ml. Once they can hold down 20 ml every 5 minutes, encourage sipping fluid frequently. While working on slow hydration, they can also be taking small licks of a popsicle, sucking on ice chips, or even on a washcloth dipped in water, juice, or a rehydration solution.

If a baby is vomiting, they should be offered a rehydration solution in small amounts like the above. This can be offered via a bottle or even a syringe. You can also make popsicles or ice cubes from frozen milk or formula that can be served in silicone or mesh feeders.

Once babies and infants are tolerating a few ounces of rehydration solution, they can be offered breast milk or half-strength formula. The half-strength formula is made by making a bottle that is equal parts normally made formula with rehydration solution. So, if you are making a 4-ounce bottle, it would be 2 ounces of normally made formula with 2 ounces of rehydration solution. Once they are tolerating the half-strength formula, then they can return to full-strength formula and normal-sized bottles. 

If your child has tolerated a few hours of fluids without vomiting, then you can start introducing food back into their diet.

Please call your provider or seek care urgently, if your child is unable to stop vomiting, can’t hold down even small amounts of fluid after a few hours, or has any of the following symptoms:

  • Prolonged fever
  • Severe abdominal pain
  • Bloody stools
  • Vomiting longer than 24 hours
  • Vomiting coffee grounds or green material (not yellow material)
  • Distended abdomen
  • Refusing to eat or drink
  • Yellow appearing skin
  • New appearing rashes
  • Signs of moderate or severe dehydration
  • Signs of mild dehydration that do not improve with increased hydration

You should also call the office if your child has a SUDDEN increase in fluid intake and is urinating more frequently than usual.

Adequate fluid intake is essential to a healthy, properly functioning body. Children are at higher risk for dehydration due to smaller bodies, greater fluid losses, and inefficient water conservation. When they are ill, it is important to provide and encourage fluid intake. If your child is showing any signs of dehydration, please do not hesitate to call for an evaluation.

Leave A Comment