Rehydration therapy (oral rehydration solution)

An educational overview of rehydration therapy, the replacement of fluids and salts lost through diarrhoea, vomiting, or fever, and why oral rehydration solution is central to it.

Treatment TherapyPediatricsFamily MedicineFull article

Also known as: oral rehydration, fluid replacement, oral rehydration therapy, ORS, ORT

Educational information only. This explains health information to discuss with a qualified clinician; it is not a diagnosis, prescription, or treatment. Medical Information & Safety.

Overview

Rehydration therapy means replacing the water and salts the body loses through diarrhoea, vomiting, or fever. Oral rehydration solution (ORS) is a specific mix of salts and sugar in clean water that the body absorbs well. This is general educational information, not medical advice.

Emergency warning signs

no urine output for many hours
sunken eyes, very dry mouth, or no tears in a child
unusual sleepiness, floppiness, or confusion
unable to drink or keep any fluid down

Evaluation & tests

Educational note: clinicians judge how dehydrated someone is from history and examination, and decide which route of rehydration is appropriate. This library does not diagnose.

Treatment education

Educational overview: rehydration is individualized by clinicians, who decide between oral solution and clinician-supervised fluids based on severity. This library does not prescribe.

Self-care

General education: prepared oral rehydration solution should be mixed exactly as the packet instructs, using clean water — stronger is not better. Continuing to feed and breastfeed during illness is widely recommended. Follow the advice of your own clinician.

When to seek care

Seek care when someone cannot keep fluids down, when diarrhoea or vomiting is prolonged, and promptly for infants, older adults, or anyone with another serious condition.