Dehydration

Consequences

Dehydration (or in other words not having enough to drink) can cause many problems, including impaired brain function making the symptoms of dementia worse, poorer balance making falls more likely, and greater likelihood of constipation and wind, urinary tract infections and pressure sores.

Causes

It's said that most people (of any age) are slightly dehydrated most of the time, but of course this is limited by their sense of thirst prompting them to drink after they've become mildly dehydrated. This sense of thirst is less sensitive in the over 60s in general, and as dementia progresses it becomes less sensitive still (eventually to the point of disappearing entirely).

Remember that in hot weather you need more to drink.

Someone who's ill and has severe or ongoing diarrhoea or vomiting may potentially need not just extra drink but oral rehydration sachets dissolved in the drink, to help keep the correct balance of sugar, salts and minerals the body needs. For old folks (who are likely to have medical issues and may be on several medications) these should only be used according to the instructions of your doctor or a qualified pharmacist. It's to be expected that your doctor would be involved in these circumstances anyway.

Promoting hydration

It's very important to make sure that your loved one has access to drink whenever they want, bearing in mind that poor memory or poor mobility may limit access. Make sure that the drink is one they like, otherwise they may only sip small amounts (for example they may much prefer diluted squash to water). If they're alone at home during part of the day then consider leaving a beaker of drink in several places. If dehydration appears to be a problem then make sure they're prompted to drink often enough.

Also see our sections on easy to use cups and on bottle unscrewing aids.

If they need assistance to drink then see our section on assisting drinking and eating.

For completeness, it should be noted that it is possible, though very unlikely, to overhydrate i.e. have too much water. This only occurs when someone drinks significantly more than is needed because they think their needs are greater than they really are (for example a marathon runner who's been told they need to hydrate, hydrate, hydrate). We do mention this, though, in case anyone becomes over-zealous in assisting drinking.

Checking for dehydration

So how do you know whether someone's dehydrated? You may have read that an (active) adult should drink approximately one and a half to two litres a day - but even as a rough guideline this isn't very helpful, since if someone needs two litres but drinks one and a half litres they'd become very dehydrated.

You might as well ask how much petrol should I put in my car each week - it depends on how far you drive, how big your car is and so on. In the absence of a good sense of thirst (equivalent to a petrol gauge), the only way to know whether someone is dehydrated is the colour of their urine (pee). Not the answer you wanted, but there it is. Ignoring the first pee of the morning after getting up, urine should be pale yellow or light straw coloured (and not smell strongly). A darker yellow colour indicates dehydration.