Hydration - Why is it so Important for Older People?

In this blog post, our expert Dietitian, Kaye Dennison (NZRD) explains why hydration is such an important issue for older people and shares her tips on how to reduce the risk of dehydration.  

Why do we need hydration?

Water is an essential nutrient which the body loses and cannot produce in the amounts it requires. It accounts for up to 80% of body weight and fills the spaces between cells, supports biochemical reactions and forms structures of large molecules like protein. Water is essential for physiological processes such as digestion, absorption and transportation.

If we do not consume water, or water containing foods or fluids regularly throughout the day, we become dehydrated.

Dehydration occurs in two ways,  either the body is short of fluid because of “low intake” and failure to drink sufficient fluids,  or due to increased fluid loss, known as “volume depletion” caused by diarrhoea, vomiting or excessive bleeding.

What really happens when we become dehydrated?

Whatever way dehydration occurs, it is serious. In normal healthy adults, thirst is the signal that stimulates us to seek fluids. Thirst is stimulated when osmolality increases or the extracellular volume decreases. Unfortunately, older people often have impaired thirst mechanisms and the signal to seek fluids is defective, which leads to dehydration.

Also, when there is insufficient fluid intake or excessive fluid loss, the kidneys compensate by producing a more concentrated urine to maintain the individual’s fluid balance. However, in older people, the kidney's ability to concentrate urine is impaired and dehydration occurs.

What are the risks of dehydration?

Older people who don’t drink enough (or have increased fluid losses) have an  increased risk of:

  • Pressure injuries
  • Low blood pressure
  • Dizziness and Falls
  • Cognitive impairment, confusion and delirium
  • Constipation
  • Urinary Tract Infections (UTIs) and acute kidney injury 
What puts older people at risk of dehydration?

There is a wide range of reasons why older people are at higher risk of dehydration than younger adults, including:

  • Decreased thirst sensation
  • Dysphagia - reduced ability to swallow thin fluids with aspirating and not enjoying prescribed thickened fluids
  • Medication commonly required by older people such as diuretics and laxatives
  • Hot weather - extreme summer temperatures will increase fluid requirements for some older people
  • Fever, diarrhoea and vomiting increase fluid losses, so more than usual fluid intake is required to make up for these losses
  • Decreased renal function in older people
  • Cognitive issues with forgetting to drink or losing the ability to drink independently
  • Inability to access or communicate the need for drinks
  • Concerns around continence – older people restrict fluid intake due to fear of having an accident
  • Inadequate staffing to meet recommended regular fluid rounds and assist residents to drink throughout the day
How do we know if the older person is dehydrated?

Simple signs and tests to assess dehydration such as skin turgor (how quickly your skin returns to normal position), urine colour or weight change are not sufficient indicators of “low intake” dehydration. A blood test (serum osmolality) is the gold standard measure to assess hydration status if necessary. However, all older people living in residential aged care facilities should be considered at risk of low intake dehydration (ESPEN 2018).    

How much fluid do older people need and how do they get it?

It’s estimated that 20% of fluid requirements will come from food and 80% of daily fluid needs from drinks.

Minimum Fluid requirements:

  • Females: 1.6L/ day
  • Males: 2L/day

On average, an intake of 30 mls/kg body weight is required to maintain fluid balance. However, individuals will vary in their requirements.

Fluids are not just limited to water, and for any older people at risk of malnutrition they should contain energy and protein (e.g. yoghurt, custards, ice-cream, smoothies, etc.).

Making drinks more exciting by adding colour, flavour and for some people increasing the sweetness, may support increased intake.

Tips for reducing the risk of dehydration
  • Put hydration plans in place for each resident with individual goals and regularly assess and review residents' fluid needs.
  • Continuous use of prompts for residents, from carers and relatives, encouraging them to regularly consume drinks.
  • Set up hydration stations for residents and visitors in shared areas with drinks the residents enjoy.
  • Encourage visitors to have a drink with residents they are visiting.
  • Provide assistance with drinking and put in place flags. For example, use different coloured coasters for patients at risk of dehydration.
  • Implement bedside wall charts identifying residents needing extra support to meet daily fluid goals.
  • Educate all members of the team; residents, relatives and all staff on the importance of fluid consumption.
  • Appoint a “Hydration Champion” in the care team to monitor hydration audit outcomes.

Then, if you still continue to have concerns about a resident’s fluid intake, consult with the facilities Doctor, Consultant Dietitian and/or Speech Language Therapist.

Want to take action now?
  1. Conduct regular fluids rounds every hour to 90 minutes during the day or as indicated in the facilities hydration guidelines
  2. Remind residents, carers, family members/whanau it is everyone’s responsibility to ensure residents get the fluids they need.
  3. Access to water is a basic human right -  Resolution 64/292, the United Nations General Assembly 2010
Stay Hydrated with Smoothies 

Smoothies are a great way for older people to get extra fluids. They are delicious and refreshing and many older people enjoy them more than water or tea - especially during the warmer summer months. And as an added bonus, they also contain extra nutrition that many older people need to stay healthy. Knowing how popular and beneficial smoothies are, we've put together a range of smoothie recipes to help you keep the people you care for hydrated this summer. Check them out here.


Learn more about how Pure Foods can help your residents

If you would like to learn more about our highly nutritious and fortified Pure Foods, and how they can help your residents stay healthy and hydrated, get in touch with us to have a chat. No strings attached. Contact us here



  • Volkert D, et al., ESPEN guideline on clinical nutrition and hydration in geriatrics, Clinical Nutrition (2018), https://doi.org/10.1016/j.clnu.2018.05.024
  • Wilson L., Hydration in older people in the UK addressing the problem. Understanding the Solutions, The International Longevity Centre- UK, November  2014
  • Nell, D., Neville, S., Bellow, R., O’Leary, C. Factors affecting optimal nutrition and hydration for people living in specialised dementia care units: A qualitative study of staff caregivers' perceptions. Australasian Journal on Ageing V 25, Issue 4, pages E1 - E6. 2016
  • Oates, L.L., & Price, C.I. Clinical assessments and care interventions to promote oral hydration amongst older patients: a narrative systematic review. BMC Nursing 16:4, 2017
  • Food and Nutrition Guidelines for Healthy Older People – A Background Paper,  New Zealand Ministry of Health,  January 2013
  • McIntyre L, Munir F, Walker S, Developing a bundle to improve fluid management, Nursing Times, Vol 108. No 28, 10th July 2012
  • George J., Rockwood K., Dehydration and Delirium—Not a Simple Relationship

The Journals of Gerontology: Series A, Volume 59, Issue 8, 1 August 2004,

Pages M811–M812, https://doi.org/10.1093/gerona/59.8.M811



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