Dehydration in Infants and Toddlers: Signs and Treatment

By , August 27th 2013. Last reviewed 9th June 2017.

Dehydration in Small Children

  • The most common cause of dehydration in small children is diarrhea.
  • Dehydration can quickly become life-threatening, so it should be treated promptly.
  • Dehydrated children under four years of age should drink oral rehydration solutions (ORS) and not plain water or other beverages with little or no sodium.
  • Mild and moderate dehydration can be treated at home.


Diarrhea due to viral gastroenteritis (stomach flu) is the most common cause of dehydration in infants and toddlers [5]. Other common causes include:

  • Refusal to drink due nausea or sore throat
  • Excessive sweating due to fever
  • Insufficient breastfeeding or formula-feeding
  • Repeated vomiting due to an infection, including food poisoning
  • More causes of dehydration

Symptoms and Signs

The signs of dehydration, such as changes in the fontanels, urination frequency, heart rate and skin turgor are presented in Chart 1 below.

Chart 1. The Evaluation of Dehydration in Infants

SYMPTOM/SIGN MILD DEHYDRATION (1-5% loss of body weight) MODERATE DEHYDRATION (6-10% loss of body weight) SEVERE DEHYDRATION (>10% loss of body weight)
Consciousness Alert Lethargic Sleepy, nonresponsive or comatose
Heart rate Slightly increased Increased Very increased
Breathing rate Normal Increased Increased
Blood pressure Normal Normal Decreased
Pulse Normal Weak Faint or undetectable
Eyes Normal Sunken; less tears when crying Very sunken; no tears when crying
Mouth and lips Normal Dry Chapped
Skin turgor test Normal Delayed (1-2 sec) Slow (skin tenting) (>2 sec)
Capillary refill <2 sec 2-4 sec >4 sec or unmeasurable
Urine excretion Slightly decreased Decreased (>6 hours without a wet diaper) Low or no urination (anuria)
Fontanel (the soft spot on the top of the head) Normal Depressed Sunken

Chart 1. Other possible symptoms of severe dehydration include constipation, irritability and seizures. Reference: 1


A doctor can make a diagnosis of dehydration in small children solely from the physical signs and observations of their parents (Chart 1). Blood and urine tests are usually performed only in severe dehydration.


Mild or moderate dehydration in infants and small children (under four years of age) should be treated with oral rehydration solutions (ORS) and NOT with plain water [6]. Severe dehydration usually requires intravenous infusion in a hospital.

Chart 2. Oral Rehydration Solution (ORS) by WHO and UNICEF

Sodium chloride (NaCl) 2.6 Sodium 75
Glucose 13.5 Chloride 65
Potassium chloride 1.5 Glucose 75
Trisodium citrate 2.9 Potassium 20
Citrate 10
Total osmolarity 245

Chart 2. The composition of Oral Rehydration Solution (ORS) by WHO (World Health Organization) and UNICEF. Reference: 2

Most commercially available oral rehydration solutions contain a little less sodium and a little more glucose than the WHO/UNICEF ORS but are appropriate to treat dehydration [6].

A Homemade ORS

A recipe recommended by WHO (World Health Organization) [4,9]:

  • 1 liter water, boiled and cooled (if boiling is not possible, use the cleanest available source of water, like bottled water)
  • 1/2 level teaspoon table salt (3 grams of sodium chloride)
  • 6 level teaspoons table sugar (~25 grams of sucrose). NOTE: 1 level teaspoon sugar = 4 grams [8].

How much ORS should you give to a dehydrated INFANT and how fast?

Initially, give ORS slowly, like one teaspoon (5 mL) per 1-2 minutes, to avoid inducing vomiting, or more if a baby can tolerate it [6,12]. Give ORS as long as a child has diarrhea or until he/she regains his/her usual body weight and his/her urine becomes clear [6]. Vomiting is not the reason to stop ORS, but if a baby vomits, wait 10-15 minutes and continue with ORS [6].

An estimated amount of fluid a baby should receive [12,13]:

  • In mild dehydration (1-5% loss of body weight): 50 mL ORS/kg body weight in 2-4 hours. If dehydration persists after 4 hours the same amount of ORS is given again.
  • In moderate dehydration (6-10% loss of body weight): 100 mL ORS/kg body weight in 2-4 hours. If dehydration persists after 4 hours the same amount of ORS is given again.
    • Additionally, for each loose stool: 10 mL/kg body weight
    • Additionally, for each vomiting: 2 mL/kg body weight
  • In severe dehydration (>10% loss of body weight): intravenous infusion in hospital as soon as possible, but ORS before that (if possible) in any amount a baby can tolerate.

You should discard ORS after it stays more than 12 hours at the room temperature or after 24 hours in refrigerator.

How much fluid should you give to a dehydrated TODDLER and how fast?

Dehydrated toddlers can drink as much ORS as they want. If an ORS is not available, they can drink other appropriate fluids (plain water, herbal tea, sport drinks, diluted fruit juice) as long as they eat some salted food [11].

Dehydrated children older than 4 years do not need ORS and can drink as much water or other appropriate beverage as they want [11].

In rare occasions, a dehydrated child might want to drink large amounts (several liters) of a fluid with no or little sodium (water, tea, fruit juice, cola), which could be due to psychogenic polydipsia. Excessive drinking without any food (and therefore salt) may lead to life-threatening hyponatremia.

Infants and Toddlers With Diarrhea

Infants and toddlers with prolonged diarrhea should receive ORS and possibly zinc supplements as prescribed by a doctor [10]. In bacterial, but not viral, diarrhea, a doctor will usually prescribe antibiotics. Antidiarrheal drugs are not recommended [6,13].

When a child has severe diarrhea, for example due to cholera, you might not be able to give him/her enough oral rehydration solution (ORS) to replace the water he/she has lost, so in this case call a doctor and continue with ORS.

Rehydration plan for cholera by

Fluids NOT appropriate to treat dehydration in infants and toddlers because they contain a lot of sugars (which may trigger diarrhea) or no or little amount of sodium (which can result in hyponatremia) [13]:

  • Plain water
  • Fruit juices (especially apple, pear and mango juice, which are high in fructose)
  • Soft drinks (soda, cola)
  • Ginger ale
  • Tea, coffee
  • Sport drinks
  • Energy drinks
  • Alcoholic drinks

What should a baby or toddler eat during dehydration?

A dehydrated baby should continue with breastfeeding or full-strength reduced-lactose or lactose-free milk formula, but he/she should additionally receive oral rehydration solution [6,13,14].

Dehydrated toddlers should eat what they like. Complex carbohydrate foods (potatoes, bread, noodles, saltine crackers, cereals), lean meats, fruits (such as bananas) and vegetables should be encouraged. Fatty foods and simple sugars should be avoided to prevent worsening of diarrhea [6,13].

When to call a doctor?

Call a doctor when a dehydrated child:

  • Is younger than 6 months
  • Has sunken eyes and fontanels, rapid deep breathing, skin turgor longer than 2 seconds, loss of more than 10% of body weight
  • Refuses to drink or does not seem to become rehydrated after giving ORS
  • Refuses to eat for more than a day
  • Vomits persistently or has severe (>10 stools/day), prolonged (>1 week) or bloody diarrhea
  • Has body temperature greater than 100.4 °F (38 °C), which may be a symptom of infection or heat exhaustion
  • Is lethargic, does not respond to physical stimuli (impaired consciousness) or has seizures (involuntary movements)
  • Has pale, cool and sweaty skin, which are symptoms of hypovolemic shock or heat exhaustion.
  • Reference: [15]

Intravenous Infusion

When an infant or toddler can not drink, vomits repeatedly or is severely dehydrated (sunken fontanels and eyes), he or she may need intravenous fluid infusion, in most cases the physiological solution (0.9% NaCl) [6].


In most circumstances, including hot climates, regular breastfeeding or consuming formula should be enough to prevent dehydration of a healthy infant. Doctors do not recommend antidiarrheal drugs for small children with diarrhea because they were not proven effective and may have side effects [6].

Prognosis and Statistics

  • Dehydration resulting in 15% loss of body weight or more (>1.5 kg in a 10 kg child) is life-threatening.
  • More than one million of young children die each year from dehydration due to diarrhea [7].
  • References

      1. Emedicine  (Dehydration Symptoms and signs)
      2. WHO  (WHO/UNICEF oral rehydration solution)
      3. WHO  (Homemade oral rehydration solution)
      4.  (Homemade oral rehydration solution)
      5. Emedicine  (Dehydration facts)
      6. Emedicine  (Dehydration treatment)
      7.  (Dehydration mortality)
      8.  (One level teaspoon is 4 grams sugar)
      9. WHO  (Homemade oral rehydration solution)
      10. WHO  (Diarrhea and zinc supplements)
      11. WebMD  (Dehydration home treatment)
      12. Emedicine  (Pediatric treatment of dehydration)
      13. CDC (The management of acute diarrhea in children)
      14.  (Diarrhea management in children)
      15.  (When to call a doctor in infant diarrhea?)