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Drinking plenty of water can help prevent dehydration.

Drinking plenty of water can help prevent dehydration.
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3-minute read

What is dehydration?

Dehydration occurs when you don't have enough fluids in your body. If severe, dehydration can cause serious problems. If you suspect you are (or someone else is) severely dehydrated, seek medical attention.

You are dehydrated if your body doesn't have enough water to keep it working properly. It can happen when your body loses too much fluid, such as from excessive sweating.

What are the signs and symptoms of dehydration?

If you have mild to moderate dehydration, you might:

  • be thirsty
  • have a dry mouth, lips and tongue
  • have a headache
  • have dark urine, and not so much of it
  • be dizzy or light-headed, particularly when standing up

If you have severe dehydration, you might:

  • be extremely thirsty
  • have a very dry mouth
  • be breathing fast
  • have a fast heart rate and a low blood pressure
  • have a fever
  • have little or no urine
  • be irritable, drowsy or confused

Babies who are severely dehydrated have a sunken fontanel, the soft spot on top of a baby’s head.

Severe dehydration is a serious problem, especially in babies and young children.

Urine colour chart
Use this urine colour chart to assess how hydrated you are.

What causes dehydration?

People can get dehydrated:

Anyone may become dehydrated, but babies, young children, older adults and people with long-term illnesses are at most risk.

How is dehydration treated?

Mild dehydration can be fixed by drinking more fluids. The simplest approach is to put 6 teaspoons of sugar with half a teaspoon of salt in one litre of boiled water. Here are instructions. You can also buy premade solutions from the pharmacy. Avoid alcohol and caffeine, as they can make you more dehydrated.

Severe dehydration needs immediate medical treatment, usually in hospital where fluids are given through an intravenous drip.

Can dehydration be prevented?

Make sure you drink enough water each day, and have extra to replace any fluid lost during hot weather, illness or exercise.

Drink lots of fluids or oral rehydration solution to treat mild to moderate dehydration. See your doctor or go to a hospital emergency room if you, your baby, child or elderly relative is severely dehydrated.

Learn more here about the development and quality assurance of healthdirect content.

Last reviewed: January 2018

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