Dehydration is loss of water from the body, usually caused by vomiting, diarrhea, or both.
Dehydration occurs when there is significant loss of body water and, to varying amounts, electrolytes.
Symptoms include thirst, underactivity, dry lips/mouth, and decreased urination.
Severe dehydration can be life-threatening.
Treatment is with fluid and electrolytes given by mouth or, in serious cases, by vein (intravenously).
Dehydration occurs when the body loses more water than it takes in. Substances called electrolytes are lost also. Electrolytes are minerals in the bloodstream and within cells that are essential to life. Sodium, potassium, chloride, and bicarbonate are examples of electrolytes.
(See also Dehydration in adults.)
Causes of Dehydration in Children
Dehydration is usually caused by
Losing too much fluid
Not drinking enough fluid
Children may lose too much fluid when they have vomiting, diarrhea, or both. However, not every episode of vomiting or diarrhea causes dehydration.
Other disorders that cause children to lose fluid include severe, widespread burns and excessive sweating.
Children may not drink enough fluid when they have a common childhood illness, such as a sore throat, or when they have a serious illness of any kind.
Some children who do not drink enough may be neglected.
Some newborns may have trouble breastfeeding (chestfeeding) or formula feeding, which occasionally may lead to dehydration.
Symptoms of Dehydration in Children
Dehydrated infants need medical care right away if
The soft spot on their head is sunken.
Their eyes are sunken.
They have no tears when they cry.
Their mouth is dry.
They are not producing much urine.
They have reduced alertness and are underactive (lethargic).
Mild to moderate dehydration typically causes a dry mouth and lips and increased thirst, and children may urinate less frequently. Children may be less interactive or playful.
Severe dehydration causes children to become sleepy or lethargic, which is a sign they must be evaluated by a doctor or taken to a hospital or urgent care clinic right away. They have no tears. They may develop a bluish discoloration to the skin (cyanosis) and breathe rapidly.
Sometimes severe dehydration causes the concentration of salt in the blood to fall or rise abnormally. Changes in salt concentration can make the symptoms of dehydration worse and can worsen lethargy. In severe cases, the child can have seizures or coma or suffer brain damage. Severe dehydration can be fatal.
Diagnosis of Dehydration in Children
Examination by a doctor
Sometimes blood and urine tests
Doctors examine children and note whether they have lost body weight. A loss in body weight over only a few days is very likely caused by dehydration. The amount of weight lost, if known, helps doctors decide whether the dehydration is mild, moderate, or severe. Doctors also base the diagnosis on the child's symptoms.
For moderately or severely dehydrated children, doctors usually do blood and urine tests to determine the levels of electrolytes in their body, the degree of dehydration, and the amount of fluid replacement required.
Treatment of Dehydration in Children
Replacement of lost fluids
Dehydration is treated with fluids containing electrolytes, such as sodium and chloride. Plain water, undiluted juice, or sports drinks are not ideal for treating dehydration at any age because the salt content of water is too low and because juice and sports drinks have a high sugar content and ingredients that may irritate the digestive tract.
If dehydration is mild, fluids are generally given by mouth. Special oral rehydration solutions are available but are not always necessary for children who have had only mild diarrhea or vomiting.
Treatment of dehydration in children of any age who are vomiting is more effective if the child is first given small, frequent sips of fluids about every 10 minutes. The amount of fluid can slowly be increased and given at less frequent intervals if the child can keep the fluid down without vomiting. If diarrhea is the only symptom, larger amounts of fluid can be given less often.
If children have both vomiting and diarrhea, they are given small, frequent sips of fluids containing electrolytes such as oral rehydration solutions. If this treatment increases the diarrhea, children may need to be hospitalized for fluids given by vein (intravenously).
Infants and children who are unable or unwilling to take in any fluids, or who develop listlessness and other serious signs of dehydration, may require more intensive treatment with fluids and electrolytes given intravenously or electrolyte solutions given through a thin plastic tube (nasogastric tube) that is passed through the nose and down the throat until it reaches the stomach or small intestine.
Infants
In infants, dehydration is treated by encouraging an infant to drink fluids that contain electrolytes. Breast milk (human milk) contains all the fluids and electrolytes an infant needs and is the best treatment when possible.
If an infant is not breastfeeding, oral rehydration solution (ORS) should be given. ORS contains specific amounts of sugars and electrolytes. ORS can be bought as powders that are mixed with water or as premixed liquids at drug or grocery stores without a prescription. The amount of ORS to give a child in a 24-hour period depends on the child’s weight, but generally should be about 1½ to 2½ ounces of ORS for each pound the child weighs (100 to 165 milliliters per kilogram). This amount helps relieve the dehydration and meet the child's daily fluid needs. Thus, a 20-pound infant should drink 30 to 50 ounces total over 24 hours (a 10-kilogram infant should drink 1,000 to 1,650 milliliters total over 24 hours).
Once infants have stopped vomiting, they should be given human milk or formula, if tolerated, as soon as possible.
Older children
Children older than 1 year may try small sips of clear broths or soups, clear sodas, gelatin, or juice diluted to half-strength with water, or popsicles. Plain water, undiluted juice, or sports drinks are not ideal for treating dehydration at any age because the salt content of water is too low and because juice and sports drinks have a high sugar content and ingredients that may irritate the digestive tract.
ORS is an alternative, particularly for moderate dehydration.
Once children have stopped vomiting, they may resume their normal diet.
