What Is Oral Rehydration Therapy for Children?

Medically Reviewed by Dan Brennan, MD on July 23, 2022
5 min read

Oral rehydration therapy (ORT) is an effective, low-cost dehydration treatment that can be given to dehydrated children. Diarrhea and the dehydration it causes can be severe and even fatal, especially for young bodies that are still developing. ORT dehydration treatment can be given to children at home as it requires no special training. 

If intravenous fluid treatment isn't available or is inconvenient to access, ORT is a good option. Oral rehydration therapy can address your child's fluid and electrolyte losses and help them avoid hospitalization.

Oral rehydration is, as the name suggests, a way to treat dehydration by mouth. This treatment uses a standardized formula to provide water, sodium, chloride, potassium, bicarbonate (or citrate), and glucose to dehydrated people, including children.

The first five of these are meant to replenish what's been lost from your child's body. Glucose is added to aid in the absorption of sodium. It also provides some energy. The formula is revised and improved by the World Health Organization (WHO) as needed.

The current oral rehydration solution approved by the WHO has the following ingredients:

  • Glucose: 75 millimols/liter
  • Sodium: 75 millimols/liter
  • Chloride: 65 millimols/liter
  • Potassium: 20 millimols/liter
  • Citrate: 10 millimols/liter

If your child has diarrhea, ORT won't stop it. This therapy aims to restore their circulating blood volume, replenish their body's fluids and electrolyte losses, and cover their ongoing losses due to diarrhea.

Diarrhea takes a lot of fluid and electrolytes out of the body. Dehydration is a danger, especially if your child is vomiting, too. But dehydration is more than just the loss of water from the body — vital electrolytes like sodium, potassium, and chloride are lost, too. Disturbed levels of these can be dangerous.

During dehydration, the loss of fluids reduces the volume of blood in circulation in the body. This causes blood pressure to drop, and tissues and organs get less blood supply. Sodium loss also contributes to this drop in blood pressure.

Mild or moderate dehydration can make your child irritable and thirsty. Their eyes may be sunken and have no tears. If dehydration progresses, your child might refuse to eat and drink, pass small amounts of dark-colored urine, and even become unconscious. Severe dehydration can be fatal if it goes untreated.

The treatment of dehydration was traditionally intravenous fluids. It was believed that people with diarrhea could not absorb fluids, electrolytes, and nutrients through their intestines, so treatment by mouth wasn't likely to be successful. Today, however, oral rehydration therapy is a successful option for dehydration treatment.

Oral rehydration therapy works by providing the required water and electrolytes in one preparation. Your doctor will assess your child and prescribe the oral rehydration treatment, and you can give it to your child yourself.

Oral rehydration solution (ORS) is available as both sachets of powder and a ready-to-use liquid. The packets are meant to be dissolved in 1 liter of water to make 1 liter of ORS. The liquid is supplied in 1-liter containers and must be consumed or discarded within 48 hours after opening. Both types have the same ingredients and benefits, but the ready-to-use solution is more expensive.

The key to success is patience. Your child won't drink a glass full of ORS in one sitting — and might even vomit if they do. This treatment requires you to give your child small amounts every 5 minutes. The amounts are defined according to age:

  • 6 months to 1 year: 1/3 ounce or 10 milliliters
  • 1 to 2 years: 1/2 ounce or 15 milliliters
  • Older than 2 years: 1 ounce or 30 milliliters

Continue giving this amount of ORS every 5 minutes for 2 hours. For mild to moderate dehydration, you should aim to give your child 50 to 100 milliliters of ORS per kilogram of body weight in 2 to 4 hours. This will correct your child's dehydration for the most part. You should continue giving them ORS afterward, but less frequently.

Every time your child has a bowel movement, give them 10 milliliters of ORS per kilogram of body weight. Once your child starts feeling better, encourage them to eat and drink things that they normally enjoy.

You shouldn't try to make ORS at home. Any errors in the composition are dangerous. Too much glucose can increase diarrhea. Too much or too little sodium and other electrolytes can cause a dangerous electrolyte imbalance. Always use the sachets as prescribed by your doctor, and measure the water used for mixing it carefully. Avoid using sodas and juices to treat dehydration — they may have too much sugar and not enough electrolytes.

Oral rehydration therapy is backed by science. It was earlier believed that the intestines were damaged by diarrhea and couldn't absorb water and electrolytes. But research revealed that your child with diarrhea can absorb sodium if it's provided along with glucose.

ORT corrects mild and moderate dehydration by replenishing the water and electrolytes lost from the body. Although the taste is quite salty, dehydrated children should take it until dehydration is corrected. ORT will be successful even if your child is vomiting. But your child's pediatrician may prescribe ondansetron, which will help reduce the vomiting.

ORT is excellent for mild to moderate dehydration caused by diarrhea. But if your child is very sick, they'll need to be hospitalized. Using precious time in a trial of ORT may be dangerous. Some situations when hospitalization is the safest option are when your child is:

  • Very drowsy or unconscious
  • Severely dehydrated (not passing urine, sunken eyes, dry mouth and tongue, cold hands and feet)
  • Frequently vomiting and unable to keep anything down
  • Under 3 months of age
  • Struggling with severe diarrhea (frequent, profuse, watery bowel movements)
  • Affected by other existing disorders (heart disease, AIDS, etc.)

Oral rehydration has been called the most important medical breakthrough of the twentieth century. It's simple technology but has the potential to reverse dehydration and save lives without expensive hospitalization. It's as effective as intravenous therapy at correcting fluid and electrolyte losses, and you can give it to your children at home with your doctor's guidance.