Dehydration in Elderly

Published: September 2, 2013
Last reviewed: March 16, 2017

Causes and Risk Factors of Dehydration in Elderly

The age by itself is not a cause of dehydration. The elderly people can be hydrated just as well as the younger ones.

Causes of dehydration in elderly are similar to causes of dehydration in other adults, for example, insufficient drinking, excessive sweating, hyperventilation, vomiting, diarrhea and excessive urination.

Risk factors for dehydration in elderly people include:

  • Decreased sense of thirst due to age or chronic diseases with pain, nausea or other symptoms that mask the feeling of thirst
  • Being bedridden
  • Living in a nursing home
  • Dementia
  • Water pills (diuretics), such as furosemide, which stimulate urine excretion

Some older people have decreased the feeling of thirst, and some avoid drinking in fear of urinary incontinence. Chronic dehydration is common in older individuals [2].

Symptoms and Signs of Dehydration

Symptoms and signs of dehydration in elderly are similar than in other adults and can include thirst, dry mouth, less frequent urination, dark urine, fatigue and headache. However, many symptoms, such as dry mouth and fatigue may be associated with age or other health conditions and not with dehydration. Wrinkled skin in old people is usually due to isolated skin dehydration and only sometimes due to whole body dehydration.

Reliable symptoms and signs of dehydration in elderly include an unintentional loss of body weight, decreased frequency of urination and dark urine. Symptoms of severe dehydration can include profound fatigue, confusion and irritability.

Assessment of Dehydration in Elderly

  • A drop of body weight by 1-3% speaks for mild dehydration, 3-6% drop for moderate, and a drop greater than 6% for severe dehydration.
  • Dark urine speaks for moderate to severe dehydration.
  • Decreased skin elasticity (poor skin turgor) is unreliable sign of dehydration in elderly.
  • Increased blood sodium level (hypernatremia) suggests dehydration.


The most common mechanism of dehydration in elderly is insufficient drinking that leads to hypernatremic dehydration (increased blood sodium levels). This type of dehydration (when mild or moderate — up to 6% loss of body weight) can be treated by drinking beverages, such as plain water or tea (about 1.5 liter of water for each kilogram of body weight loss).

Severe dehydration (>6% body weight loss) may need intravenous fluid infusion.


Old people often have decreased sense of thirst so it is important they drink regularly even when not thirsty.


Old people, when dehydrated, are at increased risk of developing [1]:

  • Bedsores or pressure ulcers (in bedridden persons or those i wheelchairs)
  • Kidney failure (in kidney patients)
  • Heart failure (in heart patients)
  • Fainting and falls possibly resulting in bone fractures (mainly in women with osteoporosis)
  • Stroke
  • Constipation
  • Memory loss
  • Hallucinations (may be a symptom of severe dehydration or a symptom of dementia, which can become worse in dehydration)
  • Infections, especially in hospitals (community-acquired pneumonia).

Dehydration and Death

Dehydration can worsen the course of certain conditions, such as heart disease or kidney disease and thus increase the risk of death. On the other hand, some otherwise healthy older people may be surprisingly resistant to dehydration.

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