What should you know about excessive dehydration?

Dehydration develops when the body loses more water and salts than it replaces. Vomiting, diarrhoea, fever, heavy sweating, heat exposure and difficulty drinking can all contribute. Signs may include intense thirst, a dry mouth, weakness, dizziness, headache, dark urine or passing urine less often. As fluid loss becomes more serious, a person may become confused, unusually sleepy, faint or unable to keep drinks down. Dehydration can occur alongside Gastroenteritis or Heat Exhaustion; the dehydration itself is the concern that guides urgency.

Move to a cool place if heat or sweating contributed. Take frequent small sips of water; an oral rehydration solution can help replace both fluid and salts, especially after vomiting or diarrhoea. Do not force a large drink if it triggers vomiting. Record roughly how often you urinate and whether symptoms are improving. People with kidney, heart or other conditions that affect fluid balance should ask a clinician how much to drink rather than rapidly increasing fluids. Avoid alcohol while recovering.

Seek urgent medical help for confusion, fainting, severe weakness, very little or no urine, rapid breathing, a fast heartbeat, severe dizziness or inability to keep fluids down. A child, older adult, pregnant person or someone with a long-term illness may worsen quickly and should be assessed early. Arrange medical advice when dark urine, thirst or reduced urination continues despite drinking, or when ongoing diarrhoea, fever or vomiting is present. Cloudy Urine, Constipation and Dark Urine have other possible explanations, so persistent changes deserve assessment.

Ask what may have caused the fluid loss, whether you need an examination or blood and urine tests, and which rehydration drink is suitable for you. Mention medicines, recent illness, heat exposure, urine changes and how much you have been able to drink.