How to know if the baby is dehydrated? 2026

Many people raise their hands when they learn that babies do not drink water, generally, until the sixth month of life.

Your first thought, logically, is that the chances of them becoming dehydrated are great because indeed, babies have a higher percentage of water in their body than adults (around 80%) and their maturity, ultimately their adaptation to high temperatures, is not that of an older person, not even that of a child. Fortunately, milk keeps them hydrated and, at the same time, fed, something that water does not do, hence one of the reasons why experts advise not giving them water in those first months of life, so that it does not quench their thirst and hunger and they drink the amount of milk they need.

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Reasons for dehydration

That said, in babies, heat is a major cause of dehydration, although this is not the only one, since it is a consequence that can occur due to a viral process that has caused them to vomit repeatedly or have diarrhea for several days. In all three cases it is essential to ensure that there are no symptoms of dehydration. What is normal, in fact, is that the newborn's demand for milk in these cases is considerably higher than usual.

Beyond this detail, which is positive because it indicates that the baby knows that he needs to drink and that is why he demands it, there are other symptoms that may be associated with dehydration: fontanels that are more sunken than usual, less pee than he usually does -unless he has sweated a lot-, dry mouth, both the lip and tongue area, drowsiness and irritability, apathy and lethargy, and weight loss, derived from that body composition rich in water, which When dehydration occurs, its percentage in the body decreases and this causes a decrease in weight, these are the signs that may be indicating that the child is dehydrated.

What to do

Some are compatible with other causes as well, hence there is no need to be unnecessarily alarmed. It is necessary to assess whether the context - weather or illness - also points in that direction and if there are no other factors that could be causing these symptoms in the baby. But, in any case and when in doubt, it is advisable to go to the pediatrician to assess whether dehydration really exists and this serious problem can be remedied as soon as possible.

For your part, try to keep the baby well hydrated at all times, increase feedings if necessary, especially in summer and if the baby is less than six months old. If you have outgrown them, water and a diet rich in fresh foods with a high percentage of water - fruits and vegetables - will also help keep the baby properly hydrated.