Can Babies Drink Water? Why Babies Under 6 Months Shouldn't
Updated: Sep 24
Quick answer: No. Babies under 6 months should not drink water. Breast milk or formula gives them all the fluid they need, even during hot Georgia summers. Around 6 months, when your baby starts solid foods, small sips of water are fine: about 4 to 8 ounces a day in total until their first birthday.
For new parents, hydration is often top of mind, especially when summer temperatures climb in Johns Creek. It's natural to wonder whether your baby needs a little water between feedings. For babies under 6 months, though, even small amounts of water can be harmful.
🧠 Why water is risky for young babies
Tiny kidneys can't handle extra water. A young baby's kidneys are still developing and can't get rid of extra water the way an older child's can. Too much water dilutes the sodium in the bloodstream. This condition is called water intoxication (hyponatremia), and it can cause:
Seizures
Brain swelling
Low body temperature
Puffiness or swelling in the face
Unusual irritability or drowsiness
Even a few ounces can upset the delicate balance a baby's body depends on.
Water crowds out nutrition. A newborn's stomach is very small. Water fills it without adding any calories or nutrients, so your baby may drink less breast milk or formula. That can slow weight gain.
🍼 Breast milk and formula are all the hydration your baby needs
Breast milk is about 88% water. Properly mixed formula has the right balance of water, electrolytes and nutrients. No extra water is needed, even in hot weather.
If your baby seems thirsty or fussy on a hot day, offer more frequent feedings. This is the safest and most effective way to keep your baby hydrated.
Always mix formula exactly as the label directs. Adding extra water to stretch formula or "hydrate" your baby is a common cause of water intoxication in infants. If you're having trouble affording or finding formula, please talk to us. We can help connect you with resources.
Signs your baby is well hydrated, and when to call
After the first week of life, a well-hydrated baby usually has at least 6 wet diapers a day and pale yellow urine.
Call your pediatrician right away if you notice:
Fewer wet diapers than usual, or dark yellow urine
A dry mouth, or no tears when crying
A sunken soft spot on top of the head
Unusual sleepiness, weakness or fussiness
What if my baby is sick?
Keep breastfeeding or formula-feeding, and offer feeds more often. If your baby has vomiting or diarrhea, don't give plain water. Call us. Your pediatrician may recommend an oral electrolyte solution in specific amounts to replace the fluids and salts your baby has lost.
When can babies start drinking water?
Around 6 months, once your baby starts solid foods, you can offer small sips of water from an open cup or straw cup with meals. Keep the total to about 4 to 8 ounces a day until 12 months. Breast milk or formula should still be your baby's main drink.
👵 But Grandma Said It Was Fine…
Well-meaning family members sometimes suggest water to soothe or cool down a baby. That advice was common a generation ago. Pediatric guidelines have changed because research shows early water can be dangerous for infants. You can share this post with them.
📍 A note for Johns Creek families
At Mindful Pediatrics in Johns Creek, we hear this question often, especially during Georgia's hot, humid summers. Your baby's hydration needs are fully met by breast milk or formula. If you're ever unsure, our team is happy to give you clear, evidence-based advice for your child.
💬 Have Questions About Infant Nutrition?
Mindful Pediatrics is here to support your parenting journey with clarity, compassion, and science-backed care. If you have questions about feeding schedules, hydration, or introducing solids, schedule a consultation or follow us on Instagram and TikTok for weekly pediatric tips.
👉 Ready to learn more? Contact us today or visit our office in Johns Creek to book an appointment with Dr. Thomas.
❓ FAQ: Why Babies Under 6 Months Shouldn’t Drink Water
Can babies under 6 months drink water?
No. Babies under 6 months should only drink breast milk or formula. Their kidneys can't safely process extra water, and even small amounts can cause a dangerous drop in blood sodium called water intoxication.
What is water intoxication in infants?
Water intoxication occurs when excess water disrupts the balance of electrolytes in a baby’s bloodstream. This can cause seizures, brain swelling, low body temperature, facial puffiness, irritability or unusual drowsiness. It needs emergency care.
My baby seems thirsty in hot weather. What should I do?
Offer breast milk or formula more often. Feeding more frequently is the safest way to keep a young baby hydrated in the heat. Keep your baby cool and out of direct sun, too.
Can I add extra water to my baby's formula?
No. Always mix formula exactly as the label directs. Over-diluting formula can cause water intoxication and doesn't give your baby enough nutrition.
Can I give my baby water for constipation?
Not without talking to your pediatrician first. Constipation in young babies has several possible causes, and your pediatrician can recommend a safe, age-appropriate treatment.
When can I start giving my baby water, and how much?
Around 6 months, when your baby starts solid foods. Offer small sips from an open or straw cup, about 4 to 8 ounces a day in total until 12 months.
What if my baby accidentally drinks some water?
A few sips are unlikely to cause harm. Watch for vomiting, puffiness, irritability or unusual sleepiness. If your baby drank more than a few ounces or shows any of these signs, call your pediatrician right away.
How do I keep my baby hydrated when they're sick?
Keep offering breast milk or formula more often. If your baby is vomiting or has diarrhea, call your pediatrician, who may recommend an oral electrolyte solution instead of plain water.
Have questions about feeding your baby?
Mindful Pediatrics supports Johns Creek families with clear, compassionate, evidence-based care. Contact us or request an appointment with Dr. Thomas. You can also follow us on Instagram and TikTok for weekly pediatric tips.
This article is for general education and isn't a substitute for medical advice. If you're worried about your baby, call our office or seek emergency care.
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