Causes of Dehydration in Small Children
The most common cause of dehydration in infants and toddlers is diarrhea due to viral gastroenteritis (stomach flu) . Other common causes include:
- Excessive sweating due to fever or hot climate
- Refusal to drink due to nausea or a sore throat
- Insufficient breastfeeding or formula-feeding
- Repeated vomiting due food poisoning or other infection
- More causes of dehydration
Symptoms and Signs
Symptoms and signs of dehydration in infants include dry mouth, less tearing when crying, sunken eyes, irritability or drowsiness, fewer wet diapers per day, strong yellow urine, poor skin turgor and constipation (more in Chart 1).
A doctor can make a diagnosis of dehydration in small children from the physical signs and observations of their parents (Chart 1). Blood and urine tests are usually performed only in severe dehydration.
Chart 1. The Assessment of Dehydration in Infants
(1-5% loss of body weight)
(6-10% loss of body weight)
(>10% loss of body weight)
|Consciousness||Alert||Lethargic||Sleepy or comatose|
|Heart rate||Slightly increased||Increased||Very increased|
|Eyes||Normal||Sunken; less tearing||Very sunken; no tears|
|Mouth and lips||Normal||Dry||Chapped|
|Skin turgor test||Normal||Delayed (1-2 sec)||Slow (>2 sec)|
|Capillary refill||<2 sec||2-4 sec||>4 sec|
|Urine excretion||Slightly decreased||Decreased (>6 hours without a wet diaper)||Very decreased or absent|
|Fontanel (the soft spot on the top of the head)||Normal||Depressed||Sunken|
Chart 1. Reference: 1
Mild or moderate dehydration in infants and children under four years of age should be treated with oral rehydration solutions (ORS) and NOT with plain water . 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|
Chart 2. The composition of Oral Rehydration Solution (ORS) by WHO (World Health Organization) and UNICEF 
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 .
A Homemade ORS
A recipe recommended by World Health Organization [3,4]:
- 1 liter of 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)
How much ORS should you give to a dehydrated INFANT and how fast?
Initially, give ORS slowly, like 1 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 . Vomiting is not the reason to stop ORS, but if a baby vomits, wait 10-15 minutes and continue with ORS .
You should discard ORS after it stays more than 12 hours at the room temperature or after 24 hours in the refrigerator.
How much fluid should you give to a dehydrated TODDLER and how fast?
Mildly dehydrated toddlers (1-4 years) can drink as much ORS as they want. If an ORS is not available, they can drink plain water, herbal tea or diluted fruit juice as long as they eat some salted food .
Dehydrated children older than 4 years do not need ORS and can drink plain water or other appropriate beverages .
In rare occasions, a dehydrated child might want to drink large amounts (several liters) of fluid with no or little sodium (water, tea, fruit juice, cola), which could be due to psychogenic polydipsia. Excessive drinking 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 . 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, 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.
Fluids NOT appropriate to treat moderate or severe dehydration in infants and toddlers include plain water, tea, coffee, soft drinks (cola, soda), sport, energy and alcoholic drinks. These beverages contain a lot of sugar, caffeine or alcohol (which may trigger diarrhea) or too little sodium (which can result in hyponatremia) .
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 [6,8,13].
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 foods simple sugars (sweets, fruit juices) 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 signs of severe dehydration (Chart 1)
- Refuses to drink or does not seem to become rehydrated after giving ORS or 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)
- 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: 
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) .
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 significant side effects .
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 .
- Huang LH, Dehydration, clinical presentation Emedicine
- WHO position paper on Oral Rehydration Salts to reduce mortality from cholera
World Health Organization
- WHO (Homemade oral rehydration solution)
- Oral Rehydration Solutions: Made at Home Rehydrate.org
- Huang LH, Dehydration Emedicine
- Huang LH, Dehydration treatment and management Emedicine
- Maughan RJ, 2003, Impact of mild dehydration on wellness and on exercise performance
- Triage of Children with Diarrhea FPNotebook
- Diarrhea Management in Children FPNotebook
- Khan WU et al, 2011, Zinc supplementation in the management of diarrhoea World Health Organization
- Dehydration home treatment WebMD
- Koyfman A, Pediatric Dehydration Treatment & Management Emedicine
- The Management of Acute Diarrhea in Children: Oral Rehydration, Maintenance, and Nutritional Therapy Centers for Disease Control and Prevention