What should you know about mild dehydration symptoms?

Dehydration happens when the body loses more fluid than it replaces. It may follow sweating, vomiting, diarrhoea, fever or simply drinking too little. Urine may become concentrated and constipation can develop. Dark or cloudy urine can have other causes, and thirst alone cannot identify the reason, so consider the whole pattern and what happened before symptoms began.

Take frequent small sips of water and continue drinking regularly as you recover. If vomiting or diarrhoea is present, ask a pharmacist or clinician whether an oral rehydration solution is suitable. Rest somewhere cool after heat exposure, and replace fluids gradually rather than forcing a large amount at once. People with kidney, heart or fluid-balance conditions should get individual advice before changing intake.

Arrange medical advice if you cannot keep fluids down, symptoms continue despite drinking, or urine becomes very infrequent. Urgent help is needed for fainting, confusion, severe weakness, fast breathing, severe abdominal or back pain, blood in vomit or stool, or signs of heat illness.

Ask what may have caused the fluid loss, how much and what type of fluid is suitable for you, and whether urine changes suggest another problem such as infection or a stone.