Signs of dehydration in children

A baby may have fewer wet nappies, a sunken-looking soft spot, a dry tongue, or appear less alert than usual. An older child may ask for drinks, pass urine less often, have dry lips, feel dizzy, or become irritable. Vomiting, diarrhoea, fever, hot weather, and heavy sweating can all increase fluid loss. Dark urine can be a clue, but urine colour alone cannot confirm the cause.

Offer frequent small sips of fluid rather than expecting a child who feels sick to drink a large amount at once. An oral rehydration solution can replace water and salts lost with vomiting or diarrhoea; follow the packet directions. Continue breastfeeding, and offer usual feeds if tolerated. Avoid giving anti-diarrhoeal medicine unless a clinician specifically advises it. Keep a record of drinks, vomiting, diarrhoea, and wet nappies.

Seek urgent medical help if a child is difficult to wake, confused, breathing unusually fast, has cold or mottled skin, cannot keep fluids down, has no urine for a prolonged period, or shows a very dry mouth with no tears. Get prompt advice for an infant with markedly fewer wet nappies, repeated vomiting, or worsening diarrhoea. A clinician should also assess dehydration after heat exposure or when an infection such as gastroenteritis may be present.

Ask which oral rehydration product is suitable, how much to offer based on the child’s age and size, and which symptoms mean the child needs same-day assessment. Mention the last wet nappy or urination, fluid intake, temperature, and any vomiting or diarrhoea.