Signs of a Dehydrated Baby

By: Sabrina Granniss, IBCLC


7 min

Do you wonder if your baby is getting enough milk? Regardless of whether feeding seems to be going well, this is a common concern in new parents’ minds. Every baby is different. Even if this is not your first baby, everything is new this time around as you and your baby get to know each other.  Initiating breastfeeding in the first hour of life, nursing frequently day and night, and keeping your baby skin-to-skin helps get your breastfeeding off to a good start and establish your milk supply. While some weight loss is normal after birth, ensuring your baby is getting enough calories and hydration for proper growth and avoiding dehydration is important.

Initial weight loss versus dehydration

It can be normal for babies to lose some weight initially after birth. By getting nursing off to a good start, they will begin to gain back that weight and be back to their birth weight or more by their second week of life. 

A baby’s body weight is 70% - 80% water. (1) A loss in total body water can quickly lead to dehydration. Dehydration happens when your baby loses more water than is being taken in when they eat. 

Dehydration can come on quickly and can happen to babies who are nursing or being fed formula. Recognizing the signs of dehydration allows you to get help sooner rather than later if you suspect a problem. If you notice signs of dehydration, contact your care provider right away.

Signs of dehydration can be mild, moderate, or severe. If you notice any signs of dehydration, even if they are mild, it is best to contact your healthcare provider since dehydration can escalate quickly in newborns. 

Milk supply and feeding frequency for newborns

Breast milk increases in volume between days 2 -5, but some parents experience a delay. (3) If your baby is really sleepy or has difficulty breastfeeding, signs of hydration should be monitored. Dehydration becomes a risk when your baby doesn’t take in enough milk over 24 hours. There is a greater risk of dehydration if the baby is not able to transfer milk well. A baby must be latched on deeply to the breast to effectively remove milk. 

It is normal for a baby to eat at least 8-12 times per 24 hours. Many parents find their baby eats more in the range of 10-15 or more times per 24 hours. (2) Keeping your baby skin-to-skin, unswaddled, will better help you notice when your baby is giving feeding cues and is ready to eat. Feeding cues include rooting, smacking, or licking their lips, turning their head to search for the breast and nipple even if their eyes are closed, or a late feeding cue of crying. 

Getting used to a new rhythm of life with your newborn and waking more often is a big transition. Babies' sleep patterns are not the same as adults'. Your baby must feed every 1.5 - 3 hours around the clock, including during the night. Being next to you helps your baby naturally rouse on their own to feed. Sharing safe sleep lets you meet the nighttime needs of your baby and allows you to get more overall sleep. (5) Keep your baby comfortable, but not in too many layers while sleeping to avoid being overheated, which can cause them to sweat and lose body water.

Indicators of hydration

Babies do sleep a lot, but if your baby is difficult to wake or not waking to be fed, this is a red flag, and you should call your doctor right away.

Babies should have 6-8 or more wet diapers per 24 hours, which is one wet diaper at least every 3 hours around the clock. A wet diaper is one that is saturated with pale yellow-colored urine with no strong odor. You can pour 2-4 Tablespoons of water on one of your baby’s clean diapers to get an idea of how a wet diaper should feel. If your baby has less than 6 wet diapers a day, this is a concern for dehydration. 

Breastmilk is very easily digested. It contains everything your baby needs, including bacteria that help in the development of their immune system. Some of the components in breastmilk do not get digested but pass through your baby’s system and are carried out in their poop. Your baby will poop anywhere from 2-5 times per day or more. (6) Reducing how much and how often they are pooping can be a warning sign for dehydration.

The skin on your baby should be plump. If your baby’s skin appears thinner or more wrinkled, this can indicate too much weight loss and possible dehydration. 

Do a pinch test - lightly pinch your baby’s skin between your thumb and index finger so it lifts. Their skin should bounce back into place easily. If there is a delay in the skin returning to normal, this is a sign of dehydration.

A fontanelle is a space between the bones of your baby’s head that will form a tight junction as it closes. It is often called their soft spot. The fontanelle on top of your baby’s head should be flat and aligned with the skull bones. If it is sunken in, dehydration should be considered. Fontanelles become closed between 9 -18 months old. 

Early signs of dehydration

  • A baby has lost fluid up to 5% of their body weight
  • Reduced number of wet diapers
  • Occasional brick dust in baby’s diaper
  • Appearance and behavior are likely normal.

Moderate signs of dehydration:

  • 6-10% weight loss

  • Baby seems irritable, and they are difficult to console
  • Dry lips or cracked lips
  • Less than 6 very wet diapers in 24 hours
  • Very loose stool or decreased number of poopy diapers
  • Urine is dark yellow or has the appearance of orange crystals
  • Cold hands or fingers, or they do not have normal color
  • Sunken fontanelle
  • Skin appears wrinkled, and skin-pinch is slow to return to normal
  • Very few or no tears when the baby cries

Severe signs of dehydration:

  • 10% or more weight loss
  • Baby is lethargic,  very hard to rouse, or becomes unconscious
  • Pulse and breathing may be rapid
  • Very sunken fontanelle
  • Skin pinch takes a long time to return to normal
  • Eyes appear sunken
  • No tears when crying

Risks for dehydration

Low milk supply may be a reason your baby is not getting enough milk. Decreased milk supply is only sometimes noticed right away. When your baby is latched on and appears to be sucking well but not having plenty of wet diapers or seems hungry after feeding, contact an IBCLC to help determine if your milk supply is affected and why that may be happening. They can suggest a plan and lactation supplements that can help increase your milk supply.

Pacifiers can interfere with noticing your baby’s cues, resulting in delayed or missed feedings until breastfeeding is well established. (7) When your baby is held and spends more time on your chest, they often eat more frequently, keeping them hydrated and happy.

Illness, including diarrhea and vomiting, can lead to dehydration. (1) These illnesses cause a lot of water loss. Diarrhea is very loose and watery poop diapers. If your baby has diarrhea or vomiting, contact your healthcare provider and IBCLC immediately. 

Certain medical conditions like Type 1 Diabetes can also cause dehydration. Type 1 Diabetes is rare and can be diagnosed at your doctor's office.

A baby may have only some dehydration signs and not all of them. Remember that learning curve we mentioned? Getting to know your baby and their cues can be easier said than done, and any breastfeeding challenges can be complicated. Your local IBCLC is there to help you uncover the root cause of feeding challenges and create an individualized care plan for you and your baby. 

Anytime you notice any signs of dehydration, it is best to contact your doctor to evaluate your baby further right away.

Wondering if your baby is getting enough milk is a common concern for new parents. Each baby is unique, and in the early days and weeks, you and your little one are getting to know each other, and everything is new. By establishing good breastfeeding practices from the beginning, including initiating breastfeeding in the first hour of life, when possible, nursing frequently during the day and night, and keeping your baby skin-to-skin, your baby will be off to a great start and reduce the risk of dehydration. Be attentive to indicators of hydration, such as wet diapers, plump skin, and regular bowel movements, while also being aware of signs of dehydration, such as weight loss, irritability, and decreased urine output. Remember, seeking guidance from a lactation consultant can help address any breastfeeding challenges and ensure your baby is well-hydrated and thriving.


Related Blogs


  1. Vega RM, Avva U. Pediatric Dehydration. [Updated 2020 Aug 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from:
  2. Lawrence & Lawrence, Breastfeeding: A Guide For the Medical Profession 8th edition, 2016, 8;267
  3. ABM 2009, Mannel et al 2013, Mohrbacher 2010
  4. Vega RM, Avva U. Pediatric Dehydration. [Updated 2020 Aug 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-
  5. Mosko S, Richard C, McKenna J. Maternal sleep and arousals during bedsharing with infants. Sleep. 1997 Feb;20(2):142-50. doi: 10.1093/sleep/20.2.142. PMID: 9143074.
  7. Jaafar SH, Jahanfar S, Angolkar M, Ho JJ. Pacifier use versus no pacifier use in breastfeeding term infants for increasing duration of breastfeeding. Cochrane Database Syst Rev. 2011 Mar 16;(3):CD007202. doi: 10.1002/14651858.CD007202.pub2. Update in: Cochrane Database Syst Rev. 2012;7:CD007202. PMID: 21412899.


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