Dehydration can occur as a result of diarrhea, vomiting, water scarcity, physical activity, and alcohol consumption.

[1] ORS is mass-produced as commercial solutions such as Pedialyte, and relief agencies such as UNICEF widely distribute packets of pre-mixed salts and sugar.

[1] Rehydration Project recommends adding the same amount of sugar but only one-half a teaspoon of salt, stating that this more dilute approach is less risky with very little loss of effectiveness.

[1][4] In what the World Health Organization (WHO) terms "some dehydration," the child or adult is restless and irritable, is thirsty, and will drink eagerly.

[1] WHO recommends that if there is vomiting, don't stop, but do pause for 5–10 minutes and then restart at a slower pace.

Begin zinc supplementation after initial four-hour rehydration to reduce severity and duration of episode.

For infants under one year of age, WHO recommends giving, within the first hour, 30 milliliters of Ringer's Lactate Solution for each kilogram of body weight, and then, within the next five hours, 70 milliliters of Ringer's Lactate per kilogram of body weight.

Patients who can drink, even poorly, should be given Oral Rehydration Solution (ORS) by mouth until the IV drip is running.

Ideally, patients should be reassessed every fifteen to thirty minutes until a strong radial pulse is present, and thereafter, assessed at least hourly to confirm that hydration is improving.

Hypokalaemia is worsened when base is given to treat acidosis without simultaneously providing potassium, as happens in standard IVs including Ringer's Lactate Solution.

In contrast, children whose food is restricted, have diarrhea of longer duration and recover intestinal function more slowly.

[1] WHO states that knowing the levels of serum electrolytes rarely changes the recommended treatment of children with diarrhea and dehydration, and furthermore, that these values are often misinterpreted.

Treatment with ORS can usually bring serum sodium concentrations back to normal within twenty-four hours.

[5] Plain water may be used if more specific and effective ORT preparations of hydrational fluids are unavailable or are not palatable.

WHO recommends that if a child vomits, to wait five or ten minutes and then start to give the solution again more slowly.