Dehydration in Children

Reviewed on 9/16/2022

What You Should Know About Dehydration in Children

Fever, vomiting, and diarrhea are common causes of dehydration in children.
Fever, vomiting, and diarrhea are common causes of dehydration in children.
  • Dehydration means that a child's body lacks enough fluid.
  • Dehydration can result from vomiting, diarrhea, not drinking enough fluids, or any combination of these conditions. Rarely, sweating too much or urinating too much can cause dehydration.
  • Infants and small children are much more likely to become dehydrated than older children or adults, because they can lose relatively more fluid quickly.

What Causes of Dehydration in Children?

  • Dehydration is most often caused by fever, diarrhea, vomiting, and a decreased ability to drink or eat associated with a viral infection.
    • Common viral infections that cause vomiting or diarrhea include rotavirus, Norwalk virus, and adenovirus.
    • Sometimes sores in a child's mouth (caused by any several viruses) make it painful to eat or drink, which helps to cause or worsen dehydration.
  • More serious bacterial infections may make a child less likely to eat and may cause vomiting and diarrhea.
  • Parasitic infections by Giardia lamblia cause the condition known as giardiasis , which can lead to diarrhea and fluid loss.
  • Increased sweating from a very hot environment can cause dehydration.
  • Excessive urination can be caused by unrecognized or poorly treated diabetes mellitus (not taking insulin) or diabetes insipidus.
  • Conditions such as cystic fibrosis or celiac sprue do not allow food to be absorbed and can cause dehydration.

What Are the Symptoms of Dehydration in Children?

Be concerned if your child has an excessive loss of fluid by vomiting or diarrhea, or if the child refuses to eat or drink.

Signs of dehydration include:

  • Sunken eyes
  • Decreased frequency of urination or dry diapers
  • Sunken soft spot on the front of the head in babies (called the fontanel)
  • No tears when the child cries
  • Dry or sticky mucous membranes (the lining of the mouth or tongue)
  • Lethargy (less than normal activity)
  • Irritability (more crying and fussiness with being inconsolable)

When Should I Call the Doctor If My Child Is Dehydrated?

Infants and small children can become dehydrated quickly.

Contact your doctor if your child has any of the following:

  • Dry mouth
  • Crying without tears
  • No urine output for over a period of four to six hours
  • Sunken eyes
  • Blood in the stool
  • Abdominal pain
  • Vomiting for more than 24 hours, or vomiting that is consistently green in color
  • Fever higher than 103 F (39.4 C)
  • Less activity than usual
  • Urination much more than usual

Go to a hospital's Emergency Department in these situations:

  • If your child is lethargic (difficult to awaken)
  • If you cannot reach your doctor
  • If your child is complaining of severe abdominal pain
  • If your child's mouth looks dry

How Is Dehydration in Children Diagnosed?

The doctor will perform a thorough history and physical exam in an effort to determine the severity and cause of the dehydration.

Specific laboratory tests may be ordered:

  • A complete blood count may identify an infection
  • Blood cultures may identify the specific kind of infection
  • Blood chemistries may identify electrolyte abnormalities caused by vomiting and diarrhea
  • Urinalysis may identify bladder infection, may give evidence of the severity of dehydration, and may identify sugar and ketones in the urine (evidence of uncontrolled diabetes).
  • In some cases, the doctor may order other tests, such as a chest X-ray, a test to check for rotavirus, stool cultures, or lumbar puncture (a spinal tap)

What Is the Treatment for Dehydration in Children?

Dehydration in children can be treated at home by replacing fluids with drinks such as Pedialyte, Pedialyte freezer pops, or any product similar that is designed to replace sugar and electrolytes. Children should take small sips every few moments. A BRAT diet may be started if vomiting has subsided for four hours. Medical treatment may include rehydration via an IV solution.

What Are the Home Remedies for Dehydration in Children?

Most children become dehydrated because of diarrhea or vomiting caused by a viral infection. The way to help a dehydrated child is to give plenty of fluids while the child is ill. This is called fluid replacement.

  • Suitable fluid replacements for children are called "oral rehydration solutions," or ORS, and include Pedialyte, Rehydralyte, Pedialyte freezer pops, or any similar product designed to replace fluids, sugar, and electrolytes (dissolved minerals such as sodium, potassium, and chloride). You can buy these products at most large grocery and drug stores.
  • For bottle-fed infants, offer ORS if the child has vomited two or more times. Offer ORS for 8 hours. If a child has vomited 1-2 times, offer a half-strength formula for two feedings, and then regular formula.
  • For breastfed infants, reduce the amount per feeding. If the child vomits twice, nurse one side every 1-2 hours. If the child vomits more than twice, nurse 4-5 minutes every 30-60 minutes. If the child continues to vomit, switch to ORS for 4 hours. Spoon- or syringe-feed small amounts of ORS: 1-2 teaspoons (5-10 ml) every 5 minutes.
  • Children older than one year may be given small amounts of clear fluids for 8 hours. Flat soda (soft drinks that are opened and then shaken to lose their fizz), Gatorade, water-based soups, popsicles, and ORS may be given for vomiting with diarrhea. Water or ice chips may be used with vomiting alone. Give small amounts (1 tbsp) every 5 minutes. After four hours without vomiting, double the amount. After 8 hours without vomiting, add solids.
  • Although it may seem that your child is vomiting all that is given, usually an adequate amount of fluid is kept down.
  • Limit solids to bland foods (any complex carbohydrates) for 24 hours.
  • Start with saltine crackers, white bread, rice, dried cereals, etc.
  • The child may resume a normal diet in 24-48 hours.
  • Discontinue all non-essential medications for 8 hours.
  • Consider acetaminophen suppositories if the fever really needs medication.

What Is the Medical Treatment for Dehydration in Children?

  • Mild: If the dehydration is mild (3% to 5% total body weight loss), the doctor may ask you to give the child small sips of Pedialyte or other oral rehydration fluids. If your child is able to drink fluids (and no dangerous underlying illness or infection is present), you will be sent home with instructions on oral rehydration, information about things to be concerned with, and reasons to return or call the health care professional.
  • Moderate: If your child is moderately dehydrated (5% to 10% total body weight loss), the doctor may place a tube into a vein (intravenous line or "IV") to provide fluids to rehydrate the child. If your child is able to take fluid by mouth after IV fluid replacement, improves after IV fluid replacement, and has no apparent dangerous underlying illness or infection, you may be sent home. When sent home, you will receive instructions on oral rehydration, instructions for close follow-up with your family doctor (most likely to be seen in the office the next day), instructions on things to be concerned about, and reasons to return or contact your health care professional.
  • Severe: If your child is severely dehydrated (more than 10% to 15% weight loss), the child will most likely be admitted to the hospital for continued IV fluid replacement, observation, and often further tests to determine what is causing dehydration. Children with bacterial infections will receive antibiotics, but viral infections will not usually require specific antibiotic therapy. In children, vomiting and diarrhea are almost never treated with drugs to stop vomiting (called antiemetics) or antidiarrheals. Such treatment would usually prolong diarrhea.

What Is the Follow-Up for Dehydration in Children?

  • Any child discharged from the Emergency Department or doctor's office with dehydration, vomiting, or diarrhea will be followed closely, either by phone, or preferably in the physician's office, the next day.
  • Continue fluid replacement as instructed by your doctor.
  • Call your doctor or return to the hospital's Emergency Department if your child seems worse, if further symptoms appear, or if you have any questions or concerns.

How Do You Prevent Dehydration in Children?

  • It is almost impossible to prevent your child from getting the viral infections that cause most cases of dehydration. The key is to recognize the danger signs early and to begin proper fluid replacement quickly.
  • If your child has vomiting or diarrhea more than four to five times in 24 consecutive hours, start fluid replacement with Pedialyte or a similar fluid to prevent dehydration. Consider keeping replacement fluid in your home for such a situation.
  • Call your doctor any time you have concerns about your child's ability to get enough fluid.

What Is the Prognosis for Dehydration in Children?

  • Most dehydration is caused by viral infections that naturally run their course. The most dangerous problem with viruses is dehydration, which can kill infants and children.
  • In most cases, providing adequate fluid, either by mouth or with IV fluid, is all that is necessary to assure your child's complete recovery.
Dehydration occurs when a person loses so much fluid his body can't function normally.

Dehydration in Adults

Symptoms and Signs

The signs and symptoms of dehydration in adults range from minor to severe.

Mild to moderate dehydration may include the following:

  • Increased thirst
  • Dry mouth
  • Tired or sleepy
  • Decreased urine output
  • Urine is low volume and more yellowish than normal
  • Headache
  • Dry skin
  • Dizziness
  • Few or no tears
Reviewed on 9/16/2022
Medically reviewed Margaret Walsh, MD; American Board of Pediatrics Pediatric Dehydration.