Dehydration in seniors: what to look (and feel) for

Water makes up about half a body's weight. It is lost through sweating, tears, urine and stools, so it needs to be replenished throughout the day, regularly.

Seniors have greater difficulty maintaining their temperature and fluids. The thirst mechanism and kidneys may not work as well as they once did, and bodies hold slightly less water. On top of that, they may be on medications such as diuretics that increase urine output, or that can affect the ability to adapt to high temperatures.

The result is dehydration, which increases the risk of kidney stones, mind confusion, and physical performance.

Generally, signs of dehydration are:

Sydney North Health Network's Dr Penny Burns, a general practitioner and disaster and emergency consultant, said as much as we need to look after ourselves, it's also imperative to look out for others who might be in an at-risk situation. To counter the risk of dehydration, she said it's simply a matter of drinking and eating enough throughout the day.

"It's more about regularity of fluid intake over the day. Regular intake of drinks and foods helps keep fluid levels up and counteract any potential dehydration," she said.

"Any fluid they wish to drink works. Water, tea or coffee, sports drinks, clear broths, ice blocks.

"Elderly people also need to have regular food, preferably with high fluid content including fruits and vegetables. And have just a little more than they usually drink depending on their activities and exposure to the heat."

She said checking urine colour is one of the best ways to check for dehydration. NSW Health's website contains a handy guide people can use as a reference to check if they're drinking enough fluid. More simply, the darker the urine, the more dehydrated a person is.

The chart is below, and available here.

A poor level of urine output, that is, not going to the toilet very often, dry mucous membranes, or a person's conscious state, are also signs of poor hydration.

Someone who is dehydrated may have low blood pressure, feel lightheaded when moving from lying or sitting position to standing, or have a faster heart rate or breathing rate. They may also be lethargic or irritable or disoriented, but this might be due to many other medical conditions as well. If that's the case, a visit to the GP would be wise.

Some vitamins or medical conditions may also darken urine. What and how much people need to drink also depends on the heat and humidity, on their activities (exercising), medications and chronic conditions.

Medicines including diuretics, antihistamines and antidepressants may affect a body's ability to regulate its own temperature, plus kidney function and the ability to sweat.

Besides having enough water, it's also important to keep cool during the heat of the day. Staying in places with air-conditioning such as a bedroom, house, or even the cinema, or shopping or community centres, are good ideas. Being in contact with people - either over the phone, or in social gatherings that promote non-alcoholic drinking including air-conditioned cafes, libraries, museums or art galleries - can help everyone's collective welfare.

Knowing where the toilet is ahead of going anywhere will also provide peace of mind that it will be OK to duck out and can have a wee safely, instead of deliberately not drink water for fear of having an accident in public.