When to see your GP

See your GP if your symptoms continue, despite drinking plenty of fluids, or if you think your baby or toddler is dehydrated.

If your GP suspects dehydration, you may have a blood test or a urine test to check the balance of salts (sodium and potassium) in your body.

Contact your GP, out-of-hours service straight away if you have any of the following symptoms:

• extreme thirst
• feeling unusually tired (lethargic) or confused
• not passing urine for eight hours
• rapid heartbeat
• dizziness when you stand up that doesn't go away after a few seconds

You should also contact your GP if your baby has had six or more episodes of diarrhoea in the past 24 hours, or if they have vomited three times or more in the past 24 hours. 

How much should I drink?

Studies have tried to establish a recommended daily fluid intake, but it can vary depending on the individual and factors such as age, climate and physical activity.

A good rule is to drink enough fluid so that you're not thirsty for long periods, and to steadily increase your fluid intake when exercising and during hot weather. Passing clear urine (wee) is a good sign that you're well hydrated.

You should drink plenty of fluid if you have symptoms of dehydration, such as feeling thirsty and lightheaded, or passing dark-coloured urine. It is also important to replace fluid lost after an episode of diarrhoea