Dehydration in the Elderly: Signs and Symptoms

Dehydration is a health condition caused by an insufficiency of fluid and electrolytes in the body. It occurs when the body utilizes or loses more water than it consumes.

What are the risk factors for dehydration in elderly?

Dehydration affects 20–30% of elderly people and is associated with higher rates of mortality and morbidity in this population. Elderly people are more prone to dehydration due to physiological alterations associated with the aging process.

A prominent age-related alteration is reduced thirst sensation (especially in Alzheimer’s and stroke patients), which leads to a reduced fluid consumption and subsequent dehydration.

Renal function also reduces with age. The reduced concentrating ability of the kidney and lack of voluntary control over urination are often related to the excessive loss of body fluids, predisposing to severe dehydration.

Cognitive problems and functional changes such as dementia and swallowing difficulties are not only more frequent in this group but lead to inadequate fluid intake.

Age-related hormonal dysregulation such as inadequate functioning of the antidiuretic hormone, vasopressin, can also lead to reduced water reabsorption from the kidney into the circulation, leading to excessive urination and subsequent dehydration. In addition, an overall decrease in body water is a frequent cause of dehydration in the elderly.

Elderly people often suffer from certain health conditions, such as high blood pressure and constipation. The use of specific medications (diuretics and laxatives) to treat these disorders often leads to dehydration due to excessive fluid loss. In addition, the presence of certain disorders such as diarrhea and vomiting can in itself increase the risk of developing dehydration.

Medications such as laxatives or diuretics could also cause dehydration.

What are the signs and symptoms of dehydration?

Mild to severe dehydration in elderly people is often associated with extreme thirst. The mouth, lips, and tongue become dry and eyes become sunken. In addition, the skin lacks elasticity.

The decrease in body fluid causes reduced frequency and amount of urination as well as the passage of dark-colored urine.

Fatigue and headache are other prominent signs of dehydration. A prolonged dehydration is also associated with low blood pressure, and rapid heart and breathing rates.

Severe dehydration can affect normal brain activity, leading to dizziness, confusion or disorientation, mood swings, shock, and even unconsciousness.

What are the outcomes of dehydration?

The consequences of dehydration in elderly people depend on its severity. It is significantly associated with an increased rate of hospitalization and mortality. Dehydration causes a two-fold increase in mortality rate in stroke patients.

Even mild dehydration is significantly related to memory impairment, lack of attention and concentration, and reduced reaction time. It can also increase feelings of exhaustion as well as the risk of falls.

Elderly people with dehydration are also prone to develop pressure sores (skin damage after staying in one attitude for a prolonged period) and other skin complications, such as dry or itchy skin.

Since proper hydration is important for normal kidney functioning, dehydration is often linked to serious kidney infections and injuries. Inadequate hydration can cause severe constipation as well.

How can one prevent dehydration?

The best way to prevent dehydration in the elderly is to identify when and why the individual is not drinking enough fluids. One of the major barriers for inadequate fluid intake is physical inability, which makes it difficult for an elderly person to reach a source of drinking water.

A fear of frequent urination or a fear of urinating before reaching the toilet is another possible reason for reduced fluid intake. This could be an outcome of reduced physical strength/ability, eventually leading to infrequent/inadequate fluid consumption.

These situations can be prevented by providing abundant water within  reach as well as help in reaching the toilet well in time. Another method could be to routinely offer water with medications and before daily physical activities.

To increase the daily fluid intake and reduce the symptoms of dehydration, it is also important to provide the elderly with fresh and palatable water or other favorite fluids, perhaps by adding a slice of fresh lime or frozen fruit to add flavor.

Further Reading

• All Dehydration Content
• Dehydration – What is Dehydration?
• Dehydration Treatment
• Causes of Dehydration
• Dehydration Symptoms

Written by

Dr. Sanchari Sinha Dutta

Dr. Sanchari Sinha Dutta is a science communicator who believes in spreading the power of science in every corner of the world. She has a Bachelor of Science (B.Sc.) degree and a Master's of Science (M.Sc.) in biology and human physiology. Following her Master's degree, Sanchari went on to study a Ph.D. in human physiology. She has authored more than 10 original research articles, all of which have been published in world renowned international journals.