Rehydration, Pediatric

Rehydration is the replacement of body fluids lost during dehydration. Dehydration is an extreme loss body fluids to the point of body function impairment. There are many ways extreme fluid loss can occur, including vomiting, diarrhea, or excess sweating. Recovering from dehydration requires replacing lost fluids, continuing to eat to maintain strength, and avoiding foods and beverages that may contribute to further fluid loss or may increase nausea.


In most cases, rehydration involves the replacement of not only fluids but also carbohydrates and basic body salts. Rehydration with an oral rehydration solution is one way to replace essential nutrients lost through dehydration.

An oral rehydration solution can be purchased at pharmacies, retail stores, and online. Premixed packets of powder that you combine with water to make a solution are also sold. You can prepare an oral rehydration solution at home by mixing the following ingredients together:

  • ⅓–⅔ tsp table salt.

  • ¾ tsp baking soda.

  • ⅓ tsp salt substitute containing potassium chloride.

  • 1 ⅓ tablespoons sugar.

  • 1 L (34 oz) of water.

Be sure to use exact measurements. Including too much sugar can make diarrhea worse.


Recommendations for rehydration vary according to the age and weight of your child. If your child is a baby (younger than 1 year), recommendations also vary according to whether your baby is breastfed or bottle-fed. A syringe or spoon may be used to feed oral rehydration solution to a baby.

Rehydrating a Breastfed Baby Younger Than 1 Year

  • If your baby vomits once, breastfeed your baby on 1 side every 1–2 hours.

  • If your baby vomits more than once, breastfeed your baby for 5 minutes every 30–60 minutes.

  • If your baby vomits repeatedly, feed your baby 1–2 tsp (5–10 mL) of oral rehydration solution every 5 minutes for 4 hours.

  • If your baby has not vomited for 4 hours, return to regular breastfeeding, but start slowly. Breastfeed for 5 minutes every 30 minutes. Breastfeeding time can be increased if your baby continues to not vomit.

Rehydrating a Bottle-Fed Baby Younger Than 1 Year

  • If your baby vomits once, continue normal feedings.

  • If your baby vomits more than once, replace the formula with oral rehydration solution during feedings for 8 hours. Feed 1–2 tsp (5–10 mL) of oral rehydration solution every 5 minutes. If oral rehydration solution is not available, follow these instructions using formula. If, after 4 hours, your baby does not vomit, you may double the amount of oral rehydration solution or formula.

  • If your baby has not vomited for 8 hours, you may resume feeding your baby formula according to your normal amount and schedule.

Rehydrating a Child Aged 1 Year or Older

  • If your child is vomiting, feed your child small amounts of oral rehydration solution (2–3 tsp [10–15 mL] every 5 minutes).

  • If your child has not vomited after 4 hours, increase the amount of oral rehydration solution you feed your child to 1–4 oz, 3–4 times every hour.

  • If your child has not vomited after 8 hours, your child may resume drinking normal fluids and resume eating food. For the first 1–2 days, feed your child foods that will not upset your child's stomach. Starchy foods are easiest to digest. These foods include saltine crackers, white bread, cereals, rice, and mashed potatoes. After 2 days, your child should be able to resume his or her normal diet.


Avoid feeding your child the following foods and beverages that may increase nausea or further loss of fluid:

  • Fruit juices with a high sugar content, such as concentrated juices.

  • Beverages containing caffeine.

  • Carbonated drinks. They may cause a lot of gas.

  • Foods that may cause a lot of gas, such as cabbage, broccoli, and beans.

  • Fatty, greasy, and fried foods.

  • Spicy, very salty, and very sweet foods or drinks.

  • Foods or drinks that are very hot or very cold. Your child should consume food or drinks at or near room temperature.

  • Foods that need a lot of chewing, such as raw vegetables.

  • Foods that are sticky or hard to swallow, such as peanut butter.


The following signs are indications that your child is recovering from dehydration:

  • Your child is urinating more often than before you started rehydrating.  

  • Your child's urine looks light yellow or clear.  

  • Your child's energy level and mood are improving.  

  • Your child's vomiting, diarrhea, or both are becoming less frequent.  

  • Your child is beginning to eat more normally.