What should you know about oral rehydration salt use?

Oral rehydration salts can be useful when diarrhoea, vomiting, fever, sweating, or poor intake causes loss of water and body salts. The glucose-and-electrolyte mixture helps the intestine absorb fluid. It does not replace a diagnosis, and it cannot correct severe dehydration when a person cannot drink or needs fluids by another route.

Thirst is not the only clue. Dry mouth, tiredness, dizziness on standing, darker urine, and passing urine less often can accompany fluid depletion. Infants may have fewer wet nappies, while older adults may show confusion or unusual sleepiness.

Use clean, safe water and the volume printed on the sachet. Mix the full contents until clear, then offer a little at a time. After vomiting, pause briefly before trying again at a slower pace. Continue breastfeeding and offer normal light foods when tolerated.

Do not use the powder dry, guess the water volume, or add extra salt or sugar. Keep the solution covered and follow the package instructions about how long it can be kept. Seek personalised advice first if there is kidney disease, heart failure, or a prescribed fluid limit.

Call emergency services for collapse, severe confusion, a seizure, serious breathing difficulty, or inability to wake. Urgent assessment is also appropriate when the person cannot swallow, repeatedly vomits every sip, or has very little urine.

Get medical advice for blood in stool, strong abdominal pain, worsening diarrhoea, or fever with pronounced weakness. A child, pregnant person, frail adult, or person with a long-term illness may need advice earlier because fluid loss can be harder to manage.

Ask what amount is suitable, how long to continue, whether other drinks or medicines should be avoided, and which symptom should prompt an urgent visit.