Dehydration (Infant/Toddler)

Dehydration occurs when too much fluid has been lost from the body. This may occur after prolonged vomiting or diarrhea, or during a high fever. It may also be due to poor fluid intake during times of illness. Symptoms include thirst, dizziness, weakness and fatigue, or drowsiness. Body fluids must be replaced with an oral rehydration solution (ORS). This is available without a prescription at pharmacies and most grocery stores.

Monitor your child for signs of dehydration. These include:

  • Dry mouth

  • Increased thirst

  • Decreased urine output or fewer wet diapers

  • Lack of tears when crying

  • Sunken eyes

  • Flat fontanelle (the soft spot on a baby’s head)

  • Increased sleepiness or sluggishness

Home care

For vomiting

To treat vomiting and prevent dehydration, give small amounts of fluids at frequent intervals.

  • Start with ORS at room temperature. Give 1 teaspoon (5 milliliters or 5 ml) every 1 to 2 minutes. Even if your child vomits, keep feeding as directed. Much of the fluid will still be absorbed.

  • Unless instructed differently by your healthcare provider, the total volume of ORS should be 5 teaspoons per pound, or 50 ml per kilogram (ml/kg) over 4 hours. If you have a 20-pound child, this will mean giving 100 teaspoons of ORS, or just over 2 cups of liquid total over 4 hours.

  • As vomiting lessens, give larger amounts of ORS at longer intervals. Continue this until your child is making urine and is no longer thirsty (has no interest in drinking). Don't give your child plain water, milk, formula, or other liquids until vomiting stops.

  • If frequent vomiting continues for more than 2 hours with the above method, call your healthcare provider.

  • After the total ORS amount is given, your child can resume a regular diet.

  • Make sure to wash hands (with soap and clean, running water) or use an alcohol-based hand sanitizer often.

Note: Your child may be thirsty and want to drink faster. But if they 're vomiting, give fluids only at the prescribed rate. The idea is not to fill the stomach with each feeding since this will cause more vomiting.

Follow-up care

Follow up with your healthcare provider as advised. Call if your child does not improve within 24 hours or if diarrhea lasts more than 1 week. If a stool (diarrhea) sample was taken, you may call in 2 days (or as directed) for the results.

When to get medical advice

Call your child's healthcare provider right away if any of these occur:

  • Repeated vomiting after the first 2 hours on fluids.

  • Occasional vomiting for more than 24 hours.

  • Frequent diarrhea (more than 5 times a day); blood (red or black color) or mucus in diarrhea.

  • Blood in vomit or stool.

  • Swollen belly (abdomen) or signs of belly pain.

  • No urine for 8 hours, no tears when crying, sunken eyes, or dry mouth.

  • Abnormal behavior changes, fussiness, drowsiness, confusion, or seizure.

  • Fever (see Fever and Children, below)

Call 911

Call 911 if your child shows any of these symptoms :

  • Trouble breathing

  • Confusion

  • Is very drowsy or hard to wake up

  • Fainting or loss of consciousness

  • Rapid heart rate

  • Seizure

  • Stiff neck

Fever and children

Use a digital thermometer to check your child’s temperature. Don’t use a mercury thermometer. There are different kinds and uses of digital thermometers. They include:

  • Rectal. For children younger than 3 years, a rectal temperature is the most accurate.

  • Forehead (temporal). This works for children age 3 months and older. If a child under 3 months old has signs of illness, this can be used for a first pass. The provider may want to confirm with a rectal temperature.

  • Ear (tympanic). Ear temperatures are accurate after 6 months of age, but not before.

  • Armpit (axillary). This is the least reliable but may be used for a first pass to check a child of any age with signs of illness. The provider may want to confirm with a rectal temperature.

  • Mouth (oral). Don’t use a thermometer in your child’s mouth until they are at least 4 years old.

Use the rectal thermometer with care. Follow the product maker’s directions for correct use. Insert it gently. Label it and make sure it’s not used in the mouth. It may pass on germs from the stool. If you don’t feel OK using a rectal thermometer, ask the healthcare provider what type to use instead. When you talk with any healthcare provider about your child’s fever, tell them which type you used.

Below are guidelines to know if your young child has a fever. Your child’s healthcare provider may give you different numbers for your child. Follow your provider’s specific instructions.

Fever readings for a baby under 3 months old:

  • First, ask your child’s healthcare provider how you should take the temperature.

  • Rectal or forehead: 100.4°F (38°C) or higher

  • Armpit: 99°F (37.2°C) or higher

Fever readings for a child age 3 months to 36 months (3 years):

  • Rectal, forehead, or ear: 102°F (38.9°C) or higher

  • Armpit: 101°F (38.3°C) or higher

Call the healthcare provider in these cases:

  • Repeated temperature of 104°F (40°C) or higher in a child of any age

  • Fever of 100.4° (38°C) or higher in baby younger than 3 months

  • Fever that lasts more than 24 hours in a child under age 2

  • Fever that lasts for 3 days in a child age 2 or older

© 2000-2022 The StayWell Company, LLC. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.

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