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Dehydration Poses Hidden Risks

July 21, 2022 - Dehydration can quickly lead to more serious health complications, particularly in seniors. Neurologist Dr. Parth Modi explains what happens and how to stay hydrated in the summer heat.

July 21, 2022

Threat from Dangerous Condition Rises in Summer Heat

Dr. Parth Modi sees it a lot: an older patient is confused, agitated, or even combative – and the cause is dehydration.

“It’s the first thing I check for when someone 75 or older shows these kinds of mental changes,” says the Virtua Health neurologist. “Dehydration is very common, especially in seniors. They may not feel thirsty due to age-related changes. So there’s a good chance they’re not drinking enough.”

Dehydration occurs when a person loses more fluids than they take in, and their body has too little fluid to work properly. It can quickly spiral into serious complications, notes Dr. Modi.

For example, this lack of liquids can cause seniors, especially, to develop urinary tract infections, which can be difficult to treat and even progress to a life-threatening illness. Dehydration can also thicken respiratory secretions, which can lead to pneumonia – a major cause of death in the elderly. It can cause dizziness, which can result in falls. And the lack of liquids can trigger constipation, which can also cause confusion in elders, among other issues.

“Problems can escalate very quickly,” Dr. Modi warns.

All ages can be affected
While they elderly are most at risk, even younger people can face significant problems – including headaches or worsening migraines. Having too few fluids can cause blood pressure to plummet, leading to dizziness, falls, and fainting.

Dehydration cases typically spike twice a year: in summer due to high heat and humidity, and in winter due to very dry indoor air, notes the physician.

Heat waves tend to put people at greater risk, especially if they spend time outdoors or don’t have air conditioning, he adds.

Elders most susceptible
Older people are more vulnerable for several reasons, explains Dr. Modi, who sees patients at Virtua hospitals in Marlton, Voorhees, and Willingboro.

  • People often lose their sense of thirst when they get older, causing them to drink too little.

  • Most older men have an enlarged prostate, which causes them to urinate more frequently. They may drink less in order to reduce their number of trips to the bathroom, especially at night.

  • Similarly, older adults are more likely to have difficulty walking and moving, leading many to drink less to reduce bathroom visits.

  • Certain medications can cause dehydration. For example, diuretic drugs – such as some blood pressure medicines – increase urination.

  • Older people’s brains are more delicate due to the normal aging process, so they are less able to compensate for a disruption such as dehydration. And those with other conditions involving the brain, such as dementia, multiple sclerosis, or traumatic brain injury, can be even more severely affected.

Tips for staying hydrated
Of course, everyone needs to drink enough, but the amount we each need can vary a lot. And it can change with the weather and our activity level.

“It’s not one size fits all,” says Dr. Modi, who offers the following advice to help prevent dehydration:

  • Drink when you feel thirsty. Water is best and healthiest. If you prefer a sports drink, dilute it with half water. If an older relative or friend will only drink soda, fill a quarter of the glass with the drink and the rest with ice.

  • Keep an eye on the color of your urine. In most cases, it should be pale yellow, like the color of lemonade. If your urine is a darker shade, then you may be dehydrated. However, B vitamins and certain medications can turn urine dark. If you have questions, check with your primary care provider.

  • People who are middle-aged and younger, with no underlying health conditions, can start with 8 oz. of water four to six times a day. If you’re sweating and/or spending time outside, you may need a lot more fluids. However, elderly people may not perspire, so a lack of sweat may not indicate whether they need liquids.

  • If you have a medical condition, ask your primary care provider how much to drink. Some illnesses, such as congestive heart failure, can be made worse by drinking large amounts. The often-cited “eight glasses of water a day” is not right for everyone.

  • Keep water nearby so it’s easy to drink throughout the day. Have a pitcher and glass where you’ll see it as a reminder.

  • If you struggle with frequent urination at night, it’s usually ok to drink most of your liquids earlier in the day. Most people can start limiting liquids after dinner, as long as they drink plenty of fluids during earlier hours.

It can be difficult to get older people to drink enough, especially if they have dementia or other neurologic conditions. You may need to take a creative approach, Dr. Modi advises. For example:

  • Make popsicles that are mainly water with some added fruit juice.
  • Serve fruits that have a high water content, such as watermelon.
  • Keep water in front of the person, with a straw to encourage frequent sips.
  • If the person prefers hot beverages, dilute decaffeinated, herbal teas with extra water.

“If you take an elderly relative to the beach or park on a hot day, make sure to push them to drink,” Dr. Modi emphasizes. “Don’t assume they will be aware of their body’s need to hydrate.”

When it comes to older folks, “it’s all about keeping the ship steady. Have a routine that helps to do that,” he advises.

To learn more about Virtua Health or find a Virtua physician, visit or call 888-847-8823. For information on the Virtua Neurosciences program, visit