Preventing dehydration

You should drink plenty of fluids t o avoid becoming dehydrated.

Most of the time, you can prevent dehydration by drinking water regularly throughout the day. Be guided by your thirst, but be aware that in hot weather, when exercising and during illness, you should drink more.

Mild dehydration can be relieved by drinking more water and diluted fruit squash. If necessary, you can purchase oral rehydration solutions (ORS) from a pharmacy. As a guide, passing pale or clear-coloured urine (wee) is a good sign that you're well hydrated.


If you're active, or if the weather is particularly hot, there's a greater risk that you will become dehydrated. To prevent becoming dehydrated, you should increase your fluid intake.

Asdifferent peoplesweat at different rates, it's very difficult to provide specific recommendations about how much fluid you should drink. However, you should drink more than normal while exercising, and it's particularly important tokeep well hydrated if you'reexercising in warm conditions. This isbecause you will sweat more and fluid will be lost from your body more rapidly.

Rarely, drinking more fluid than your body can process can reduce theamount of sodium (salt) in yourblood. This can lead to a serious and potentially fatal conditioncalled hyponatremia . If you start to feel discomfort and bloating from drinking, stop drinkingand allow time to recover.


If you, your child or someone you are caring for is ill, particularly witha fever , vomiting or Traveller's diarrhoea , there's a high riskof becoming dehydrated, so it's important to start replacing fluid as soon as possible.

Advice for children

There are no specific recommendations regarding the amount of water or other fluids that children need.

However, it's important for children to replace lost fluid, to prevent dehydration. Like adults, children lose more water when they are in hotter climates and when they are physically active.

You should give your child healthy drinks as part of an overall healthy, balanced diet .

See the page on drinks and cups for more information and advice on specific drinks for young children.

Content supplied by the NHS Website

Medically Reviewed by a doctor on 28 Nov 2016