How to Rehydrate My Baby
Medically reviewed by Dr. Sarah Chen, MD, FAAP · Board-Certified Pediatrician
Content reviewed against published AAP, WHO, CDC guidelines
Last reviewed:
Digestive issues are common in infants and toddlers. If your baby is experiencing how to rehydrate my baby, here is what you need to know.
The short answer
The best way to rehydrate a sick baby is to offer breast milk, formula, or a commercial oral rehydration solution (like Pedialyte) in small, frequent amounts. For breastfed babies, nurse more often in shorter sessions. For formula-fed babies and toddlers, offer an oral rehydration solution in small sips every few minutes. Avoid giving plain water alone to babies under six months, juice, soda, or sports drinks, as these can worsen diarrhea.
Key takeaways
- The best way to rehydrate a sick baby is to offer breast milk, formula, or a commercial oral rehydration solution (like Pedialyte) in small, frequent amounts. For breastfed babies, nurse more often in shorter sessions. For formula-fed babies and toddlers, offer an oral rehydration solution in small sips every few minutes. Avoid giving plain water alone to babies under six months, juice, soda, or sports drinks, as these can worsen diarrhea.
- Usually normal when: Your baby is taking small frequent sips of oral rehydration solution or breast milk and maintaining wet diapers during an illness
- Call your doctor if: Your baby cannot keep any fluids down for more than eight hours or is showing signs of worsening dehydration despite your rehydration efforts
- Varies by age — see the age-by-age breakdown below
“The biggest concern with vomiting is dehydration. Young children can become dehydrated quickly, so it's important to replace fluids. Offer small amounts of an oral rehydration solution frequently.”
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What Parents Should Know
According to AAP, WHO, CDC guidelines, the best way to rehydrate a sick baby is to offer breast milk, formula, or a commercial oral rehydration solution (like Pedialyte) in small, frequent amounts. For breastfed babies, nurse more often in shorter sessions. For formula-fed babies and toddlers, offer an oral rehydration solution in small sips every few minutes. Avoid giving plain water alone to babies under six months, juice, soda, or sports drinks, as these can worsen diarrhea. At 0-6 months, breast milk and formula are the primary rehydration fluids for babies under six months. If your breastfed baby is vomiting, try nursing for shorter periods more frequently. For formula-fed babies, your pediatrician may recommend offering small amounts (one to two tablespoons) of oral rehydration solution between formula feeds. Do not dilute formula or give plain water to babies under six months without medical guidance, as this can cause dangerous electrolyte imbalances. It is generally considered normal when your baby is taking small frequent sips of oral rehydration solution or breast milk and maintaining wet diapers during an illness. However, you should contact your pediatrician promptly if your baby cannot keep any fluids down for more than eight hours or is showing signs of worsening dehydration despite your rehydration efforts.
Normal vs. Concerning
By Age
What to expect by age
0-6 months
Breast milk and formula are the primary rehydration fluids for babies under six months. If your breastfed baby is vomiting, try nursing for shorter periods more frequently. For formula-fed babies, your pediatrician may recommend offering small amounts (one to two tablespoons) of oral rehydration solution between formula feeds. Do not dilute formula or give plain water to babies under six months without medical guidance, as this can cause dangerous electrolyte imbalances.
6-12 months
Continue breastfeeding or formula feeding as the primary source of hydration. You can now also offer small sips of water and oral rehydration solution between feeds. If your baby is vomiting, wait about 30 minutes after a vomiting episode, then offer one teaspoon of oral rehydration solution every two to three minutes. Gradually increase the amount as your baby tolerates it. A medicine syringe can help deliver small precise amounts.
12-24 months
Toddlers can drink oral rehydration solution from a cup or sippy cup. Offer small, frequent sips rather than large amounts at once. If your toddler refuses the rehydration solution, try offering it cold, as ice pops made from the solution, or mixed with a very small amount of juice for flavor. Continue offering normal foods as tolerated, as eating helps the gut recover. Avoid giving large amounts of apple juice or sugary drinks, which can worsen diarrhea.
24-36 months
Older toddlers may be more cooperative with drinking but may also have stronger preferences. Oral rehydration solution popsicles, small cups with straws, and gentle encouragement all help. Once vomiting has stopped for a few hours, gradually reintroduce a normal diet. Broth-based soups, crackers, and bland foods are good starting points. If your child continues to refuse all fluids, contact your pediatrician, as IV rehydration may be needed.
What to Tell Your Pediatrician
- Describe when you first noticed how to rehydrate my baby and how it has changed over time.
- Note your baby's current age and which age-specific patterns you are seeing.
- Mention if you are unsure how much fluid to offer your baby or which products are appropriate for their age.
- Mention if your baby has been sick for more than 24 hours and you want to confirm your rehydration approach is working.
- Bring a list of any questions or observations you want to discuss at the appointment.
What Should You Do?
When to take action
- Your baby is taking small frequent sips of oral rehydration solution or breast milk and maintaining wet diapers during an illness
- Your baby vomits occasionally but is able to keep down small amounts of fluid between episodes
- Your toddler is drinking less than usual but is still producing wet diapers and gradually improving
- Your child's energy and mood improve after rehydration and they begin asking for food
- You are unsure how much fluid to offer your baby or which products are appropriate for their age
- Your baby has been sick for more than 24 hours and you want to confirm your rehydration approach is working
- Your baby cannot keep any fluids down for more than eight hours or is showing signs of worsening dehydration despite your rehydration efforts
- Your baby under three months is refusing to feed, your baby has bloody diarrhea or vomit, or your baby is extremely lethargic, has a sunken fontanelle, or has not had a wet diaper in more than six hours
What You Can Do at Home
- Keep track of when you notice how to rehydrate my baby — noting the time of day, duration, and any triggers can help your pediatrician.
- Remember that your baby is taking small frequent sips of oral rehydration solution or breast milk and maintaining wet diapers during an illness — this is generally within the range of normal.
- At 0-6 months, focus on observation rather than intervention unless your pediatrician advises otherwise.
- Keep your baby upright for 20-30 minutes after feeding. Note any patterns between feeds and symptoms.
- While monitoring at home, seek immediate care if your baby cannot keep any fluids down for more than eight hours or is showing signs of worsening dehydration despite your rehydration efforts.
Related Resources
Vomiting Decision Tree
Evaluate vomiting severity and decide when to call the doctor.
Poop Color & Texture Guide
What your baby's poop color and consistency mean, and when to worry.
Month-by-Month Development
Detailed monthly development guides from birth through 24 months.
When to Call the Doctor
General guide on when to call the pediatrician, visit urgent care, or go to the ER.
Frequently asked questions
Is how to rehydrate my baby normal?
When should I call the doctor about how to rehydrate my baby?
When is how to rehydrate my baby normal?
What causes how to rehydrate my baby?
What should I mention to my pediatrician about how to rehydrate my baby?
Is how to rehydrate my baby normal at 0-6 months?
Is how to rehydrate my baby normal at 6-12 months?
Should I go to the ER for how to rehydrate my baby?
Does how to rehydrate my baby go away on its own?
References
Doctor Visit Checklist
Bring this checklist to your next pediatrician visit to discuss How to Rehydrate My Baby.
Things to mention
- Describe when you first noticed how to rehydrate my baby and how it has changed over time.
- Note your baby's current age and which age-specific patterns you are seeing.
- Mention if you are unsure how much fluid to offer your baby or which products are appropriate for their age.
- Mention if your baby has been sick for more than 24 hours and you want to confirm your rehydration approach is working.
- Bring a list of any questions or observations you want to discuss at the appointment.
Observations to share
- You are unsure how much fluid to offer your baby or which products are appropriate for their age
- Your baby has been sick for more than 24 hours and you want to confirm your rehydration approach is working
Urgent signs to report immediately
- Your baby cannot keep any fluids down for more than eight hours or is showing signs of worsening dehydration despite your rehydration efforts
- Your baby under three months is refusing to feed, your baby has bloody diarrhea or vomit, or your baby is extremely lethargic, has a sunken fontanelle, or has not had a wet diaper in more than six hours
My notes
From ismybabyalright.com — free, evidence-based baby health guides
All content follows our editorial policy and is reviewed against published clinical guidelines.
2,705 evidence-based guides6 authoritative medical sources5 medical advisory board members
Related Resources
Bottom line
Most cases of how to rehydrate my baby are normal. Talk to your pediatrician if your baby cannot keep any fluids down for more than eight hours or is showing signs of worsening dehydration despite your rehydration efforts.
Trust your instincts. If something feels wrong, reach out to your pediatrician. Worrying about your baby means you care — that is a good thing.
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