Dehydration in Older Adults: Signs, Symptoms and Causes You Need to Know

Up to 75% of the human body is made up of water. Without adequate hydration, the body cannot function properly.

As we age, the natural feeling of thirst becomes less dominant. This is particularly common in older adults, including people living with dementia or those who have experienced a stroke. As a result, dehydration can occur before thirst is even felt, making it easy to miss the early warning signs.

Dehydration can lead to a range of serious health consequences if left untreated. This resource provides helpful information on what dehydration is, the signs and symptoms of dehydration in the elderly, and common factors that increase the risk as we age.

What Is Dehydration?

Dehydration occurs when the body does not have enough fluids to carry out its normal functions.

Dehydration can range from:

• Mild to moderate dehydration, which is usually resolved quickly and without medical treatment

• Severe dehydration, which can be life-threatening and requires immediate medical attention

Older adults are at a higher risk of dehydration due to changes in the body, health conditions, and lifestyle factors.

Common Causes of Dehydration in the Elderly

As we age, dehydration can result from many different factors, including:

• Depression or poor cognition (dementia)
• Severe vomiting and/or diarrhoea (e.g. gastroenteritis)
• Diseases such as diabetes or declining kidney function
• Fever
• When taking too many medications such as diuretics or laxatives
• Limited mobility
• Simply not drinking enough – whether that be from fatigue, confusion and forgetfulness (dementia), swallowing issues, needing thickened fluids, feeling unwell, lack of thirst and appetite or needing help to drink
• Incontinence – avoiding drinking to avoid heeding to go to the toilet.

Signs and Symptoms of Dehydration in Older Adults

Older adults may present with one or multiple symptoms of dehydration, and signs can vary from person to person. Common symptoms to look out for include:

• Confusion or delirium

• Dry skin and cracked lips

• Dizziness or feeling light-headed

• Headaches or migraines

• Low blood pressure

• Constipation

• Nausea

• Fatigue or increased tiredness

• Dry mouth

• Dark-coloured urine (dark yellow) or reduced urine output

• Increased thirst

Early recognition of these symptoms is essential to prevent dehydration from becoming severe.