Stay hydrated for health

Lesley Dobson / 31 July 2014

Did you know that dehydration can cause confusion and impaired brain function? Find out how to stay hydrated.



We need water to help us function properly, and to help control our body temperature, and to carry nutrients and oxygen to the trillions of cells in our bodies. Fluids also help carry waste out of our bodies, and help keep our digestive system, joints and eyes lubricated.

Drink more water in the heat 

Drinking more fluids when the temperature’s high may sound like obvious advice. But it’s advice worth following, because we don’t always realise when we are becoming dehydrated. And that’s something that happens increasingly as we grow older.

There are reasons why this happens more in our mature years. As we grow older the signals that our bodies send out to tell us that we’re thirsty or hungry, become weaker. So we may need to top up our fluids, but may not notice because our system isn’t telling us as efficiently as it used to.

Dementia and hydration

People who have Alzheimer’s disease or dementia, and those who have had a stroke, have trouble swallowing or have poorly controlled diabetes can struggle to stay hydrated. Some medicines, such as laxatives and drugs that help you pass urine can make you more likely to be dehydrated. And our kidneys may become less efficient as we grow older, with the result that we lose more water and need to drink more to replace it.

Another common condition in our older years – incontinence – can make us dehydrated too, as we drink less to avoid the embarrassment of not being able to control our bladders. But being embarrassed may not be the worst problem. One side effect of dehydration is confusion and impaired brain function, which can be mistaken for a more serious condition.

In an episode of the popular TV series Doc Martin, one of the older characters didn’t drink enough as she was worried about wetting the bed during the night. She became dehydrated, and confused and disorientated. These symptoms were mistaken for dementia, and she was admitted to a residential/care home until Doc Martin made the right diagnosis.

How much should we drink?

The European Hydration Institute suggests that once we’re over 50 we should make sure that we drink regularly, even if we aren’t feeling thirsty. “Drinking about 1.5 to 2 litres of water or other fluids a day is a good ballpark figure,” says Registered Dietitian Sue Baic, spokesperson for the Association of UK Dietitians. “But if it’s very hot, or you’re doing something very active, drink more. Bigger people will probably need more fluids a day, and smaller people may need less.

More information on how much water to drink each day

Tea and coffee

If you aren’t drinking as much as you used to, or have some signs of dehydration, it can be a good idea to get into the habit of having a drink at certain times of the day. So you could have water or juice and tea or coffee with your breakfast, a hot or cold drink at 9.30 and again at 11.00, and a drink with your lunch, and another afterwards. Making a habit of drinking at regular times may help you drink enough to stay hydrated. Remember to add extra drinks when it’s hot.

“One and a half to two litres of fluid, works out at roughly six to eight glasses or mugs of fluid a day,” says Sue Baic. “So another way of making sure you drink enough is to have at least one drink with your meals, and one in between. That adds up to six servings, so you just need to add two more. The important thing is to get into a habit or pattern of drinking at certain times.”

Learn more about the health benefits of tea and coffee

Avoid drinking spirits 

What should you drink? “Water, tea, herbal tea, coffee, milk and fizzy drinks, all help to hydrate you,” says Sue Baic. “Spirits, on the other hand, tend to be diuretic – and make you pass more urine. If you do drink spirits, for each alcoholic drink have a soft drink too.”

Fluids don’t just come from drinks. “You can get around ¾ of a litre a day from foods,” says Sue Baic. “If you eat five portions of fruit and veg a day, that should give you about 500 mls (0.87 pints) of water.

Are you drinking more alcohol than you think?

Where does it all go?

We lose fluid from our bodies all the time, through normal bodily functions. We lose about 400mls (0.7 pints) from our lungs, just by breathing, 500 mls (0.87 pints) through urine, and 200 mls (0.35) through faeces (poo). We can lose around 500-700ml (0.87pints) through sweat, but on a particularly hot day, or if we’ve been doing something very energetic, this can go up considerably.

Symptoms of dehydration

If you are concerned that you or anyone else might be dehydrated, there are some quick and easy ways of checking if you’re running dry.

  • Producing dark, strong-smelling urine
  • A dry mouth and/or dryness under the arms
  • Being confused and disorientated
  • Feeling more tired than usual
  • Feeling weak and dizzy
  • Sunken eyes
  • Loose or slack skin

As well as making you feel ill, being dehydrated can cause urinary tract infections and, because it can make you feel dizzy, can increase your risk of falling.

If you have any of the symptoms shown above, or are concerned that you or someone else might be dehydrated, have something to drink straight away. Water with a little sugar stirred into it is a good choice, but most other drinks such as tea, herbal tea, coffee, milk and fizzy drinks will help to rehydrate you.

Have something to drink straightaway 

If you or someone else becomes severely dehydrated, act at once. The signs can include the symptoms above as well as being delirious, difficulty breathing, low blood pressure, a weak pulse, fainting and possibly even fits. This is a medical emergency and you must call for medical help immediately.



The opinions expressed are those of the author and are not held by Saga unless specifically stated.

The material is for general information only and does not constitute investment, tax, legal, medical or other form of advice. You should not rely on this information to make (or refrain from making) any decisions. Always obtain independent, professional advice for your own particular situation.