8 questions about thirst

1. Why are the elderly at greater risk of dehydration?

Young, healthy people do not dehydrate so quickly, even when it is very hot. As soon as the body loses a lot of fluid, an imaginary bell rings in the brain that causes a feeling of thirst, so that people drink. In the elderly, from the age of 65, this system works less and less well. Certainly above 80 it decreases. Then it can happen that someone forgets to drink. Anyone who also takes medicines that affect fluid balance (such as diuretics) and, for example, gets a stomach flu, runs a high risk of dehydration.

2. What happens in the body when it dries out?

With an initial deficiency, the body will lose the moisture present as little as possible. The perspiration is therefore on the back burner. That is unhealthy, because sweating ensures that the body temperature does not rise when it is warm. The kidneys will also produce less urine. Little need to go to the toilet (less than once every three to five hours) is therefore a first sign of dehydration. Fluid then flows from the cells into the bloodstream, so that the amount of blood and blood pressure are maintained. This causes the cells to dry out slowly. You can notice that on the skin; if it stays upright when pulled up briefly, that could also be a sign of dehydration.

The brain cells are also sensitive to dehydration. This manifests itself in confusion. When moisture still doesn’t get in at this stage, dehydration becomes really harmful. The sodium balance is disturbed and the blood pressure drops. This makes you feel light-headed and can lead to fainting. If the fluid and sodium levels are not replenished, shock and coma can result. So drinking is so important.

3. How dangerous is a heat wave for the elderly?

During the heat wave in 2010 (five days in a row warmer than 25 ºC, three of which at least 30 C), about 500 older people died more than usual in such a period, according to figures from Statistics Netherlands. However, dehydration is not the main reason for those extra deaths. This usually concerns people with heart or lung problems. Dehydration initially causes all kinds of health problems that can lead to hospitalization. For example, it increases the risk of infections and kidney stones. Too little fluid can also lead to thrombosis. American research shows that of all over-65s who are hospitalized, 7 percent have a fluid deficiency.

4. If dehydration is easy to spot, why is it so common?

It is less easy to diagnose in the elderly. For example, the simple test with pulling up the skin does not work; older skin is usually drier and always ‘stands’ for a while. A symptom such as confusion is also not always recognizable, especially when someone is suffering from dementia. And sweat less? The elderly already do that anyway. There are other ways to check whether someone is drinking enough, but they are time-consuming and sometimes just not feasible. Roads, for example. This makes it possible to calculate how much fluid a person ingests and loses. But this is very drastic, especially for bedridden people.

‘Simply’ ensuring that a dependent elderly person drinks enough is also easier said than done. Sometimes the swallowing reflex is no longer in order. There is also not always enough staff in nursing homes to help a large part of the residents to drink at least two liters a day. Add to that the fact that informal carers are sometimes also absent during the summer because of holidays, and the problem is clear.

5. How do you ensure that elderly people in need drink enough when it is warm?

With simple tricks. For example, don’t just put down water, tea, coffee or fruit juice, but also take a glass yourself, sit down and have a drink together. Pour again when the glass is empty. Or both eat an ice cream cone. A bowl of juicy fruit is also a great way to get extra moisture. If you are going on holiday yourself, make sure there is someone else who will keep an eye on things and take the time to have a drink together. If you are a caregiver for a dependent elderly person who lives independently, please contact your GP to ask whether any medication needs to be adjusted to the warm weather. The staff keeps an eye on people who live in a nursing or care home.

6. And how do you ensure that you get enough fluids yourself?

By drinking at least two liters a day on hot days. This often happens automatically. But if you a lot of sweat or if you exercise, it is necessary to drink extra. If the sweating decreases, you have to go to the toilet less often, the urine becomes darker and you get a light-headed feeling, then there is probably a starting fluid deficiency. An (isotonic) sports drink is a good way to supplement this. A glass of lemonade is also good. Or make your own drink that supplements sugar and salt: a glass of water with a tablespoon of sugar and a teaspoon of salt. Not recommended for people with high blood pressure.

7. Beer is also moisture, isn’t it?

Correct. And of course a beer on a hot day is no problem. Lots of beers or other alcoholic beverages. Alcohol acts as a diuretic. Alcohol also has an insidious side: it can seem as if that drink causes confused behavior, when in reality a lack of fluid in the brain is the cause. Coffee and tea do count towards the minimum two liters that must be drunk per day.

8. Which diseases and medicines do you have to pay extra attention to when it is hot?

At least with the use of diuretics, so water tablets. It is wise to consult with your doctor or specialist about an adjusted dose when it is warm. This also applies to people with heart failure or angina pectoris. These conditions can be associated with lowered blood pressure, and then a lack of fluids (with an even lower blood pressure as a result) is an extra risk.

People with diabetes should also pay attention. If the glucose level is high, this is passed out and there is fluid loss that needs to be replenished. There are also medications that affect sweating. A side effect of antidepressants can be increased sweating. This moisture must be replenished. Medications for Parkinson’s disease, allergies and incontinence can actually counteract sweating, so that it is less noticeable that it is hot and that more needs to be drunk.