What to expect from oral rehydration therapy for dehydration

Dehydration means the body has lost more fluid than it has replaced. This can follow diarrhoea, vomiting, fever, heavy sweating or difficulty drinking. Oral rehydration solution combines water with glucose and salts so the intestine can absorb fluid efficiently. Thirst and dry mouth may ease first, while urine output, energy and dizziness can take longer to improve.

Choose a prepared oral rehydration solution or follow a clinician’s instructions. Measure the water accurately and use the solution within the time stated on its packaging. Sip often rather than drinking a large amount at once, particularly if nausea is present. Continue normal food if tolerated. Avoid relying on very sugary drinks or alcohol, which may worsen fluid loss or upset the stomach. Read more about [Dehydration](/conditions/dehydration/) and [Oral Rehydration Therapy](/treatments/acute-and-urgent-care/oral-rehydration-therapy/).

Get urgent medical help if you are confused, faint, unusually drowsy, unable to drink, vomiting repeatedly, passing very little urine, or becoming weaker despite sipping. Seek advice promptly for a baby, older adult, pregnancy, kidney disease, heart disease or another condition that affects fluid balance. Severe dehydration may require monitored treatment in a medical setting.

Ask how much solution is appropriate, how long to continue it, whether medicines need adjustment, and how you can tell that hydration is returning.