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Leaflet: Keeping hydrated

Nutrition and Dietetics Service

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Last updated: August 2020
Next review: August 2022
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What do we mean by hydration?

Water makes up over two-thirds of the healthy human body. It is essential for lubricating the joints and eyes, aiding digestion, flushing out waste and toxins and keeping skin healthy.

Dehydration occurs when the normal water content of your body is reduced, upsetting the delicate balance of minerals (salts) and sugars in your body. Many of your body’s cells depend on these minerals being maintained at the correct levels to function properly.

What are the symptoms of dehydration?

Symptoms of dehydration include:

  • dark urine
  • feeling thirsty
  • light-headedness
  • dizziness
  • headaches and tiredness
  • reduced alertness
  • reduced ability to concentrate

Most people should aim to drink 1600 – 2000 mls (around 6 – 8 glasses) of fluid per day to stay hydrated unless otherwise advised by a doctor or specialist nurse. Keeping hydrated can aid the treatment of constipation, and prevent low blood pressure, urinary tract infections (UTIs), pressure injuries and falls.

Top tip: Use a measuring jug to find out the volume of your cups and glasses at home as some hold more fluid than you think!

Image showing different drinking options

Did you know?

Around 20% of our daily fluid intake comes from within our food. See ‘Hydration Boosters’ resource for more information.

  • Do not wait until you feel thirsty to have a drink; thirst is a late response to dehydration.
  • Use the pee chart (top of this page) to score your hydration status as the colour of your urine can indicate dehydration risk.
  • Serve drinks at their optimum temperature and replenish any drink that has been left to stand.
  • Replace fluid that is lost through sweat, open wounds, diarrhoea or vomit to prevent dehydration.
  • You will sweat more in warm conditions and when you are more active.
  • Limiting your fluid intake can make incontinence worse because it reduces your bladder’s capacity.
  • Increase your fluid intake earlier in the day if you worry about urinating at night.
  • Fit your fluid intake around your daily routine and take a bottle with you on the go.
  • Spout cups, handled mugs or plastic tumblers may be lighter and easier to handle.
  • If you are at risk of malnutrition choose nourishing fruit or milk based drinks. (see ‘Super Shakes’ resource for recipe examples).
  • Choose water, skimmed milk or sugar-free drinks if you have diabetes and/or are trying to lose weight.