Water Intoxication in Infants

Published: November 20, 2013
Last reviewed: December 22, 2017

How much water can cause water intoxication in babies?

According to the Pediatrics journal, as little as 8 oz (~240 mL) of plain water in a day–in addition to breastfeeding or formula–can cause a drop of blood sodium levels (dilutional hyponatremia) in an infant younger than 6 months; this is known as water intoxication or poisoning (11).

Fruit juices, tea and soft drinks and other beverages that contain little or no sodium can also cause water intoxication.

Symptoms may include vomiting, epileptic attack (seizures), coma or even death.

Frequently Asked Questions

1. Do breastfed infants need additional water?

According to US Department of Agriculture and one 1990 study in India, healthy breastfed infants 0-12 months of age, including those living in hot climates with temperatures as high as 104 °F or 40 °C, can get all the water they need from breast milk (which contains 88% of water), so they do not need any additional water (1,16,17).

The same way, formula prepared according to instructions, should meet the infant’s need for water. Do NOT dilute the formula from any reason.

2. Is it safe to give water to a constipated infant?

Infants 6-12 months of age who are bottle fed or get some solids can get 4-8 oz of water per day (1,5).

3. Is gripe water safe for constipation or colic in infants?

Gripe water should not be used as a remedy to treat colic or constipation in infants, especially not in newborns (4). Gripe water does not likely treat colic, it can promote infections and, in case of overdose, diarrhea or hypernatremia (4).

4. How to treat or prevent dehydration from diarrhea in infants?

An infant or toddler who is dehydrated due to diarrhea or other cause should be breastfed or get formula more frequently or should be treated with an oral rehydration solution (ORS) or in severe cases, with intravenous fluid, and not with plain water, commercially available “nursing water,” fruit juices, tea, soda or other beverages that contain little or no sodium (14).

Symptoms and signs of dehydration in infants include dry lips, less tears when crying, less wet diapers (>6 hours without a wet diaper) and prolonged skin turgor (>1 sec).

When not sure how much your baby should drink, contact a doctor.

Mechanism of Water Intoxication

The infant’s kidneys are immature and cannot excrete a lot of of water quickly, so feeding a baby with excessive plain water may results in water retention and a drop of blood sodium levels (dilutional hyponatremia), which in turn can lead to brain swelling (cerebral edema).

Symptoms and Signs

  • Irritability, drowsiness, lethargy
  • Vomiting
  • Excessive urination: >6-8 wet diapers a day
  • Swelling around the eyes (periorbital edema)
  • Low body temperature (hypothermia): <97 °F or 36.1 °C
  • Excessive sweating (diaphoresis)
  • Seizures (facial twitches, lips smacking, rolled-back eyes, rhythmic jerky movements of the arms and legs)
  • Death
  • References: (1,2,8,12,18)

Causes of Water Intoxication

1. Giving Water to Babies

Some parents dilute baby formula with water to save money and some give water to infants between formula.

Water intoxication reports in news:

  • A 20-day old girl was fed by 2 oz of milk formula and additional 4 oz of water every 4 hours, and after one day of such feeding she developed hyponatremia with seizures and lost consciousness. She was successfully treated with no complications (3).
  • Another newborn, an 8-day old boy, was fed by 2 oz of milk formula every 2 hours followed by 2 oz of water for several days before he developed seizures and lost consciousness. He was successfully treated by anticonvulsants and intravenous infusion of a hypertonic fluid (3).
  • A 7 months old girl was given 1.8 liters of water in 24 hours. She developed hyponatremia (116 mmol/L) with seizures, but survived after treatment (10).

2. Maternal Overhydration During Labour

A news report:

  • In y. 2008 in the UK, a mother has drunk 3-4 liters of water in an 8-hour period during labour. Her baby boy developed seizures at 3 hours after birth; his blood sodium level was 124 mmol/L (normal = 135-145 mmol/L). The infant was treated by fluid restriction and intravenous fluid infusion and recovered without complications (12).

3. Tap Water Enema, Colon Irrigation

Enema using large amounts of plain water can cause water intoxication in infants (14), especially in those with megacolon (Hirschsprung’s disease), because megacolon can absorb much more water than healthy colon (7).

4. Swimming Lessons

During swimming, an infant can swallow enough water to develop hyponatremia with seizures within few hours after swimming (6,13).

Diagnosis and Treatment

Diagnosis and treatment of water intoxication is much like in adults. The blood test shows low sodium levels.

Treatment, which should be performed in a hospital, can include water deprivation, intravenous saline infusion, diuretics and anticonvulsants (in seizures).


Prompt treatment of hyponatremia usually result in complete recovery without complications. Severe hyponatremia, treatment delay or inappropriate treatment can result in death or neurological complications, such as mental retardation or cerebral palsy (15).

  • References

      1. Water Intoxication  US Department of Agriculture
      2. Too Much Water Raises Seizures Risk in Babies  Johns Hopkins Children Center
      3. Vanapruks V et al, 1989, Water intoxication and hyponatraemic convulsions in neonates  BMJ.com
      4. Adhisivan B, 2012, Is gripe water baby-friendly?  PubMed Central
      5. Is it safe for babies to drink water?  New York Times
      6. Water intoxication in infants  Children’s Hospital, St. Louis
      7. Ziskind A et al, 1958, Water Intoxication Following Tap-Water Enemas  The JAMA Network
      8. Pediatric Hyponatremia Clinical Presentation  Emedicine
      9. 2011, Guidelines for offering water to breastfed babies  Kellymom.com
      10. Wong KC, 2002, Water intoxication in a 7-month infant  Hong Kong Journal of Pediatrics
      11. Bruce RC et al, 1997, Hyponatremic Seizures Secondary to Oral Water Intoxication in Infancy: Association With Commercial Bottled Drinking Water  Pediatrics
      12. Shivashankar G et al, 2008, Neonatal seizure due to maternal water intoxication in labour – a case report  Infant
      13. 1987, Swimming and water intoxication in infants  PubMed Central
      14. Ramakrishnan K et al, 2003, Enemas: A “Purge” Atory  Ispub.com
      15. Moritz ML et al, 2009, New aspects in the pathogenesis, prevention, and treatment of hyponatremic encephalopathy in children  PubMed Central
      16. Composition of human milk  US Department of Agriculture
      17. Almroth S et al, 1990, No need for water supplementation for exclusively breast-fed infants under hot and arid conditions  PubMed
      18. Medani CR, 1987, Seizures and hypothermia due to dietary water intoxication in infants  PubMed

10 Responses to Water Intoxication in Infants

  1. I was half asleep and fed my son 3oz of plain water. He will be 2 months in 2 weeks and 5 days. I did this at 6:30am in the morning. He’s seemed fine all day. Its currently 12:04pm. He seemed like he was still hungry as soon as I took the water away so I made him a formula bottle (4oz water with 2 scoops formula) he eat the entire bottle. Of course his stomach was extremely full. I spotted it by rubbing it and and hr or something later give gripe water. He takes gas drops with everything bottle (mixed with formula) he eats every 3 hrs in the dot. He hasn’t missed a feeding and has clearly let me know when its time. Should I be worried? Temp is good. It’s hot here so he’s sweaty. He’s naturally clammy anyways and he’s always fussy due to gas from the formula. He’s naturally sleeping all day except feedings and diaper changes. He is awake some throughout the day but mostly asleep. He’s not jumpy out of his normal since he’s still new. No swelling that I can see. Checked fever 1hr after water and it was 99. Something. Haven’t checked it anymore. If he had water intoxication would I already be able to tell? How long does it take before he’s in the clear? He seems his normal self.

  2. Bree says:

    What should someone do if they accidentally gave their child purified water with their formula without boiling it??

  3. Everly says:

    I have been using a Baby Brezza and have already confirmed that I set it up properly. It was recently determined that, for whatever reason, it has been dispensing the wrong amount of formula into the water. Due to this, my son has been getting diluted formula for about two weeks now. He is only a month old.

    He has been very irritable and varies between sleeping a ton and refusing to sleep at all. He has also had more than 6-8 wet diapers per day. Since he is a newborn, his movements are slightly “jerky” anyway, so I can’t measure that part.

    Is this an ER or doctor visit? When I called his pediatrician, they just scheduled an appointment for tomorrow morning like it wasn’t a big deal. Should I take him to the ER?

    • Jan Modric says:

      You did not mention any amount of water given and in what period, so I can’t judge this. If you are worried, take him to ER.

  4. Sarah jayne says:

    Can you advise of the frequency of the occurances? You seem to suggest this happens all the time. Please can you clarify

  5. Lynne says:

    If a 1month old is given 50 mls of water and a teaspoon of sugar and may be suspected of water intoxication,how soon would it show signs of this

    • Jan Modric says:

      Within several hours. If nothing happens within 12 hours, it’s less likely water intoxication. Babies should not really take extra water. On the other hand, 50 mL may not result in a disorder with noticeable symptoms.

  6. Josephine reblora says:

    What will happen if a 1 month old infant was given 2oz water with half teaspoon of sugar,because they think she was constipated not having poop in 4days,she was formula fed and breastfed?

    • Jan Modric says:

      If she is breastfed or formula fed sufficiently, she will get enough water from that. She probably gets about 1 liter of water from her feeding, so 2 oz of additional water will not likely help in constipation. In general, infants, especially as young as 1 month should not get any plain water. One occasion with 2 oz of water probably did not do any harm, but they should not continue with this. A doctor can examine her and say what can be done.

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