Rehydration Therapy

Cholera can cause dehydration, which can be deadly if not properly treated. With timely rehydration therapy, more than 99% of cholera patients will survive. That’s why rehydration is the most important treatment for cholera.

Rehydration therapy for patients with cholera can include

  • adequate volumes of a solution of oral rehydration salts,
  • intravenous (IV) fluids when necessary, and
  • electrolytes.

When patients with cholera are not treated with rehydration therapy, at least 1 in 4 to close to half of them can die from the disease.

Key Points About Rehydration
  • Rapid high-volume rehydration will save lives.
  • Many patients can be rehydrated entirely with oral rehydration solution (ORS).
  • Even if patients get intravenous (IV) rehydration, they should start drinking ORS as soon as they are able.

Watch the following video: Managing Dehydration.

Signs and Symptoms of Dehydration

Severe Dehydration
One or more danger signs:

  • Lethargic or unconscious
  • Absent or weak pulse
  • Respiratory distress

OR at least two of the following:

  • Sunken eyes
  • Not able to drink or drinks poorly
  • Skin pinch goes back very slowly

Some Dehydration
No danger signs AND at least two of the following:

  • Irritable or restless
  • Sunken eyes
  • Rapid pulse
  • Thirsty (drinks eagerly)
  • Skin pinch goes back slowly

No Dehydration

  • Awake and alert
  • Normal pulse
  • Normal thirst
  • Eyes not sunken
  • Skin pinch normal

Oral Rehydration Guidance: No to Some Dehydration

  • Give oral rehydration solution (ORS) immediately to dehydrated patients who can sit up and drink. If ORS is not available, you should provide water, broth, and/or other fluids. You should not provide drinks with a high sugar content, such as juice, soft drinks, or sports drinks, because they could worsen diarrhea.
  • Offer ORS frequently, measure the amount drunk, and measure the fluid lost as diarrhea and vomitus.
  • Give small, frequent sips of ORS to patients who vomit, or give ORS by nasogastric tube.
    • Make ORS with safe water, which is water that has been boiled or treated with household bleach or a chlorine product using the dose recommended in the product’s instructions, at least 15 minutes before adding prepackaged oral rehydration salts. To make the solution, mix the oral rehydration salts (a prepackaged sachet of glucose and electrolytes) with 1 liter of safe water.
  • A rough estimate of oral rehydration rate for older children and adults is 100 ml of ORS every 5 minutes, until the patient stabilizes.
  • The approximate amount of ORS (in milliliters) needed over 4 hours can also be calculated by multiplying the patient’s weight in kg by 75.
  • If the patient requests more than the prescribed ORS solution, give more.
  • Patients should continue to eat a normal diet or resume a normal diet once vomiting stops.
  • For infants: encourage the mother to continue breastfeeding.


  • Reassess the patient after 1 hour of therapy and then every 1 to 2 hours until rehydration is complete.
  • During the initial stages of therapy, while still dehydrated, adults can consume as much as 1,000 ml of ORS per hour, if necessary, and children as much as 20 ml/kg body weight per hour.
  • The volumes and time shown are guidelines based on usual needs. If necessary, you can increase the amount and frequency, or you can give the ORS solution at the same rate for a longer period to achieve adequate rehydration. Similarly, you can decrease the amount of fluid if the patient becomes hydrated earlier than expected.

Intravenous Rehydration Guidance: Severe Dehydration or Shock

  • Patients should receive intravenous (IV) rehydration if they have
    • severe dehydration,
    • stupor,
    • coma,
    • uncontrollable vomiting, or
    • extreme fatigue that prevents drinking.
  • For severe dehydration, start IV fluids immediately. If the patient can drink, give ORS by mouth while the IV drip is set up. Ringer’s lactate IV fluid is preferred. If not available, use normal saline or dextrose solution.
  • It is important to measure the amount of IV fluids delivered and measure the fluid lost as diarrhea and vomitus.


  • Reassess the patient every 15–30 minutes and continue hydrating. The volumes and time intervals shown are guidelines provided on the basis of usual needs.
    • If necessary, you can increase the rate of fluid administration, or you can give the fluid at the same rate for a longer period, to achieve adequate rehydration. If hydration is not improving, give fluids more rapidly; the patient may need 200 ml/kg or more of intravenous fluids during the first 24 hours of treatment.
    • You can decrease the amount of fluid if the patient becomes hydrated earlier than expected.
    • Give more than the prescribed ORS solution if the patient requests more.
  • Switch from intravenous hydration to oral rehydration solution once hydration is improved and the patient can drink. This will conserve IV fluids and reduce the risk of phlebitis and other complications.
    • You can use nasogastric tubes to administer oral rehydration solution if the patient is alert but unable to drink sufficient quantities independently.
Fluid Replacement or Treatment Recommendations
Dehydration Type Treatment Recommendation Administration Method
Severe dehydration Intravenous Ringer’s lactate or, if not available, normal saline and ORS as outlined in the guidance above. Do not give plain glucose or dextrose solution. Administer as follows:
<1 year
Timeframe Total volume
0–60 min 30 ml/kg*
60 min–6 h 70 ml/kg
6 h–24 h 100 ml/kg
Administer as follows:
≥1 year
Timeframe Total volume
0–30 min 30 ml/kg*
30 min–3 h 70 ml/kg
Some dehydration Oral rehydration solution Administer in first 4 hours:
All ages
Volume of ORS
75 ml/kg in first 4 hours. Then reassess, and if patient still shows signs of dehydration, repeat. If not, use ORS to replace ongoing diarrheal losses using the treatment plan for no dehydration below.

Patients do not need IV fluids, but need close monitoring during the first 4 hours

No dehydration Oral rehydration solution Administer after each loose stool:
Age Volume of ORS
<2 years 50–100 ml
2–9 years 100–200 ml
≥10 years As much as patient wants

*Repeat once if radial pulse is still very weak or not detectable

Signs of Adequate Rehydration
  • Skin goes back normally when pinched
  • Thirst has subsided
  • Urine has been passed
  • Pulse is strong
Special Populations

Patients with severe acute malnutrition

Patients with severe acute malnutrition should receive oral rehydration with low-osmolarity ORS instead of the standard rehydration solution for diarrhea, ReSoMal, which does not have sufficient sodium content to replace the losses from cholera. More information is available in WHO’s guidelines for inpatient treatment of severely malnourished infants and children. Breastfed infants should continue to breastfeed. If ORS is not available, provide water, broth, and/or other fluids; avoid fluids high in sugar, such as juice, soft drinks, and sports drinks.

Pregnant women

Pregnant women with cholera are at a higher risk of fetal loss compared with the general population of pregnant women, and dehydration should be treated promptly. Dehydration can be difficult to assess and may be underestimated during the later stages of pregnancy. Closely monitor the patient’s degree of dehydration, response to treatment, and systolic blood pressure.