“Thousands have lived without love, not one without water.” — W.H. Auden

It always comes back to water. No matter the current health trends, diet fads, or fancy new-age products, water remains a simple but necessary constant in maintaining good health and proper body function. From kidney function to clearer skin, staying hydrated offers a tsunami of health benefits.

For older people, those benefits come with a catch: Unlike their younger counterparts, older adults’ symptoms of dehydration often don’t include feelings of thirst. That means keeping track of more than your own parched throat when it comes to staying hydrated.

Now combine that decreased sense of thirst with physical changes that can cause older people to dehydrate faster than they used to, and the stage is set for serious — often fatal — medical issues.

First of all, older adults have a lower volume of water in their bodies than their younger counterparts: Men aged 25 to 54 comprise 54.3% water on average, while those aged 61 to 74 comprise just 50.8%. Women average 48.6% and 43.4% water, respectively, at the same ages. (Men’s lower percentage of water can be traced back to muscle mass and and expenditure of energy.)

Second, the physiological and hormonal mechanisms that regulate kidney function become less responsive over time. Younger people urinate less when they’re dehydrated, while older people tend to excrete fluid at the same rate regardless of whether they’ve topped off recently.

Finally, older people often take medications with diuretic effects that cause them to lose water more quickly. And those who are cognitively or physically impaired are less likely to fetch themselves a drink or ask for one.

Since older people are already running drier than their younger counterparts, they run a greater risk of the most extreme outcomes of dehydration.

Remaining water in the body may flow rapidly from the brain, damaging it irreparably; elderly patients are far more prone to this dramatic shift than younger people.

Meanwhile, irritation of dehydrated muscle and nervous tissue can bring on seizures, and drying renal and circulatory systems can cause kidneys and hearts to shut down.

Once an older person is disoriented by dehydration, catastrophic physical trauma can occur within hours.

With the summer season approaching, it’s a perfect time to take stock of your own water-drinking habits and see if you — or someone in your care — are properly prepared to handle the increased heat and humidity.

As most of us learned in science class, the body uses water in all its cells, tissues, and organs to maintain temperature and function properly.  

Water aids in digestion, and it protects joints, tissues, and vital areas like the spinal cord and brain, and is crucial in the removal of waste from the body. The list goes on and on.

But how much is enough? And what are some signs that you’re not drinking enough water and might be dehydrated?

What is the suggested daily water intake?

That’s a complicated question. A common rule of thumb you may have grown up with is for your daily water intake to be eight eight-ounce glasses (64 ounces) — but ask any doctor and you’ll likely get a different answer. If you’re looking to tailor your water quantity to your specific needs, you can try a calculation from Dr. Carolyn Dean, M.D., N.D.

Dr. Dean says to drink one-half your body weight (in pounds) in ounces of water. So if you weigh 140 pounds, you should drink 70 ounces of water a day, which is 2.2 liters, and would be slightly more water than simply drinking eight glasses of water.

Dr. Asim Cheema, MD and medical advisor on Your Doctors Online, sets the bar higher. According to Dr. Heema, “Broadly speaking, on average a person should consume between 3 and 5 liters of water per day.”

That is considerably more than Dr. Dean’s formula suggests, and speaks to the range of opinion on healthy water intake.

A note on gender: While men generally need to consume more water than women because of their greater body mass, neither doctor advised that men’s greater percentage of body water requires additional consumption.

What are the clearest signs of dehydration?

Dehydration, much like daily water intake, can vary from person to person, and symptoms can depend on a person’s age and whether they suffer from other medical conditions.  

Dr. Cheema provided some details: “In older children and adults, some of the signs that may point to dehydration are weakness, having a dry mouth, light-headedness, and dizziness.”

Among older adults, symptoms of dehydration can be more confusing.

Among older adults, symptoms of dehydration can be more confusing. “Elderly people may not feel thirsty or show other common signs of low body water and may instead appear drowsy, confused, or disoriented if they’re dehydrated,” Dr. Cheema told Considerable. “Therefore, extra caution and care should be provided for the elderly to maintain adequate hydration by regular and timely water and fluid intake.”

It’s important to note that dehydration can set in long before symptoms start to emerge. You may not feel thirsty or experience any dizziness, and yet you could still be in need of water.

A good way to keep tabs on your level of hydration is to pay attention to how often you’re going to the bathroom — and what you see when you do. If you haven’t peed for long stretches of the day and if your urine is dark, then you’re dehydrated.

Some common myths about hydration and dehydration

Dr. Dean is categorical on this subject: “The worst myth is all you need is water to handle dehydration or to stay hydrated.

“Proper hydration must include minerals, as water alone does not properly hydrate the body.”
Dr. Carolyn Dean

“We need minerals with water. Proper hydration must include minerals/electrolytes, as water alone does not properly hydrate the body. Water follows minerals inside the cells where it is necessary for optimum metabolism and cellular hydration.”

Her recommendation? Add one-quarter teaspoon of sea salt to every quart of water you drink.

Meanwhile, Dr. Cheema offers up some bad news for anyone convinced that water is a literal fountain of youth. “A common myth is that good water intake can slow down the aging process. Water definitely helps keep you healthy, but it would not slow down the process of aging.”

He also warns against using water for weight loss: “While water can replace other beverages or drinks which have a higher calorie content, it can not trigger weight loss on its own.”

Room-temperature water vs. cold water

Everyone has their own preference for water temperature. Does the temperature of the water you drink affect your body?

Dr. Cheema says yes. “Room temperature water is always recommended. When you consume cold water, your body has to redirect blood supply from other organs to the stomach to lower down the temperature of the water.”

“Cold water slows digestion, [and] it can partially solidify fats and oils in the stomach, further slowing digestion.”
Dr. Carolyn Dean

Dr. Dean agrees. “Cold/ice water takes more energy to process because your body has to warm it up. Cold water slows digestion, [and] it can partially solidify fats and oils in the stomach, further slowing digestion.”

Like most things, common sense will serve you well when it comes to water. Make sure you’re drinking consistently throughout the day, especially if you’re sweating a lot or working in a hot environment.

Pay attention to how you feel. If you notice you haven’t gone to the bathroom in several hours, or if your urine is dark, then you need to drink some water. Not feeling thirsty doesn’t always mean your body is hydrated enough.  

And don’t underestimate how much better you’ll feel when well-hydrated. It might not slow down the aging process or magically make you skinnier, but it is a key element to maintaining a healthy lifestyle, and your body will thank you for it.