6/15/17: SWEATING IN THE SUMMERTIME: Be Wary of Dehydration, Especially in Elders, Whose Sense of Thirst Is not as Acute


In 2010, my then-86-year-old mother suffered from dehydration, a common and potentially deadly problem for older people. At the time, both she and my father were convalescing at home from fractures and had paid caregivers looking after them full-time. I popped in to check on them and to take them to appointments.  

Imagine my surprise when Mom crumpled to the floor in a faint upon returning with me from the orthopedist’s office. It was only then that my still-cognitively-sharp physician father advised me that Mom had been lightheaded lately upon rising—a sign, he surmised, of low orthostatic (standing) blood pressure.

Dr. Al also thought Mom might have blood clots in her legs because they had become telltale swollen and shiny. Just three months before, Mom’s cardiologist—who had told her after she suffered a near-fatal pulmonary embolus in 2006 that she would be on the anticoagulant warfarin (Coumadin) for life—had switched her to aspirin. Unbeknownst to me, Dad had been consulting by phone with Mom’s primary-care doctor about her hypotension and leg edema.    

Earlier, Mom’s caregiver “Sophie,” who was a certified nursing aide provided by an agency, had confided to me that my mother wasn’t eating lunch and wasn’t drinking much water. I had been stunned by this report and asked Sophie to insist that Mom eat and drink. Sophie didn’t consider such directness part of her job, however, and wasn’t comfortable with coaxing Mom. I didn’t pay as much attention to Sophie’s aversion as I should have. I falsely assumed that a home-care nurse would ensure that her elderly and obviously forgetful patient didn’t become dehydrated! And that she would notice if her patient’s legs filled with fluid! Wrong and wrong.

Mom ended up in the hospital, and I stayed by her side as much as I could through her treatment and post-discharge rehabilitation. It turned out that Sophie was a personal friend of the owner of the home nursing agency, who was giving her “another chance” in hiring her. Since this fiasco, I’ve relied on word-of-mouth referrals to caregivers and avoided agencies. I’m also more hands-on.

The following is an edited excerpt from my book, “Our Parents in Crisis: Confronting Medical Errors, Ageist Doctors, and Other Healthcare Failings,” about dehydration:


Water Is Life

Studies suggest that, if untreated, 50 percent of adults 65 and older with dehydration will die.

Water sustains human life. Dehydration occurs when you lose more fluid than you take in, and your body doesn’t have enough water and other fluids to function normally. This life-threatening condition happens disproportionately among elders living in institutions and, sadly, reflects neglect. (My mother had Sophie to ensure that she wasn’t neglected. So, what the heck, right? Lesson learned.)

Water makes up about 60 percent of an adult male’s body weight, and 50 percent of a woman’s, and is involved in all of your body’s chemical processes, such as digestion, circulation, excretion, nutrient transportation, and maintenance of blood volume and body temperature. Although water is distributed throughout your body, the water content of adipose tissue (fat) is relatively low. Women generally have a higher percentage of body fat than men, hence the lower percentage of water in their body weight.

Your body’s water exists in two different compartments. The intracellular fluid compartment contains all of the fluid inside your cells and makes up two-thirds of your total water content. This water is potassium-rich, oxygen-consuming, and metabolically active. The extracellular fluid compartment, which has special subcompartments, such as the cerebrospinal fluid and the humors of the eyes, contains all of the fluid outside of your cells and accounts for the other third.  

Your body continuously loses water:

·        Through your kidneys in the form of urine (excess water);

·        Through your skin in the form of sweat;

·        Through your lungs as moisture in your breath; and

·        Through your gastrointestinal tract in elimination

You replace the water you lose by producing more on your own and by consuming foods and beverages.

As a young or middle-aged person, you may experience thirst, fatigue, weakness, queasiness, and discomfort with a 1 to 2 percent loss of fluid—maybe after being in the sun too long without fluid replenishment.

A 3 to 4 percent loss of fluid will cause you to experience impaired physical performance (e.g., weakness), dry mouth, flushed skin, reduced urine, and apathy. At 5 to 6 percent, headache, sleepiness, irritability, difficulty with concentrating, and adverse effects on body temperature and respiration occur. Severe dehydration, quantified as a 7 to 10 percent loss of body water, can lead to cerebral edema, seizures, kidney failure, coma, and death. It is unquestionably a medical emergency.  

Older adults’ fluid intake and fluid losses are different. Some physiological events occur with aging that increase the likelihood of dehydration. Among the changes, an older person’s sense of thirst becomes less acute, and his or her body loses some of its ability to conserve water. Older people, especially if they live and/or eat alone, tend to eat much less than younger people and may forget to eat or drink.

Changes in functional status, brought on by cognitive impairment, effects of medication, incontinence, mobility disorders, bed rest, etc., further put older people at increased risk for dehydration. The elder taking a diuretic (as my mother sometimes did) is losing water; the incontinent elder may be afraid of drinking; and the mobility-impaired elder may be unable to reach a water glass.

Geriatricians at Harvard Medical School advise that dehydration in older people should be identified by a “rapid weight loss of greater than 3% of body weight.” They estimate that the daily fluid intake requirement for adults 65 and older should be 30 milliliters per kilogram of body weight. Thus, a 160-pound person should be drinking between eight and nine cups of fluid per day.

These same experts say that early diagnosis of a fluid and electrolyte crisis in an older person can be difficult because the classical physical signs may be vague, absent, or misleading. (I talk more about electrolytes, which are vital body chemicals, in other chapters.) Also, most elders who are hospitalized with dehydration have an underlying acute illness, such as pneumonia, influenza, gastroenteritis, or a urinary tract infection, which confounds a diagnosis.

Constipation is a common symptom among fluid-depleted elders. Abnormal declines in orthostatic blood pressure, as my mother had, also may signal dehydration.

One sure way to gauge your [older parent’s] need for fluid is by the color of her or his urine. Clear or light-colored urine indicates good hydration; a dark yellow or amber color suggests dehydration. If there’s little or no urination, your parent may be in the danger zone, symptomatized by low blood pressure, a rapid heartbeat and rapid breathing, fever, and, in the most serious cases, delirium or unconsciousness.

My mother did not sufficiently hydrate herself, and Sophie did not consider it her job to monitor her water intake. Just like in the hospital, Mom had a water bottle at her bedside, but we did not check to ensure that she drank from it! We thought that was why we had Sophie. We also thought Mom could be trusted to ensure her own hydration. She could not.

When we asked later why she hadn’t been drinking, Mom said either: “I wasn’t thirsty” or “I forgot.” This is an honest answer for an older person, regardless of his or her cognitive status. We had to wise up fast.


In a book chapter on “The Aging Body,” in which I discuss normal age-related physiological changes that occur in the body’s various systems, I examine changes in the integumentary system, which includes the skin. It is well-known that age causes the epidermis, which is the visible outermost skin layer, to thin, and impairs wound healing. This is because, between the ages of 30 to 80, the turnover rate of epidermal-cell replacement slows about 30 to 50 percent. Epidermal cells, which take abuse from the sun and other environmental elements, must be continuously replaced, a process that takes about 28 days in young skin.

Relevant to the discussion above, I write in this chapter:

Because of the age-related decline in the density of the dermal blood supply,* which provides oxygen and nutrients to the tissues and an efficient means by which to regulate body temperature, elders become more vulnerable to sunburn. This decreased density, coupled with a gradual loss of functioning sweat glands, also predisposes your Mom and Pop to heat stroke.

*With age, the dermal microvasculature (blood vessels) becomes more fragile and subject to rupture. Not only do you lose vessels, thus reducing your skin’s blood supply, but you lose the fatty subdermal layer that helps to protect vessels from injury. The dermis is the middle layer of skin between the epidermis and the subcutaneous tissue, aka hyodermis.


Ann, 6/15/17

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