Dehydration in older people

While hospital food and malnutrition is often in the news, dehydration is also an important concern. 

Risk factors for dehydration

Older people are vulnerable to dehydration due to physiological changes in the ageing process, but this can be complicated by many disease states, and mental and physical frailty that can further increase risk of dehydration.

Age-related changes include a reduced sensation of thirst, and this may be more pronounced in those with Alzheimer’s disease or in those that have suffered a stroke. This indicates that thirst in older people may not be relied on as an indicator of dehydration.

Reduced renal function is also a risk factor. The kidneys play a vital role in fluid regulation but their function deteriorates with age, and the hormonal response to dehydration (which is key to fluid balance) may be impaired.

Dehydration is more common in those with cognitive impairment and changes in functional ability. Swallowing difficulties, dementia and poorly controlled diabetes are more common in older people and are all associated with poor hydration.

Preventable dehydration in care settings, whether residential or hospitals is an indicator of poor quality care. And whist it may be preventable it would seem that it is still too common in the older person. Improving hydration can bring well-being and better quality of life for patients, allow reduced use of medication and prevent illness.

The likelihood of dehydration may also be exacerbated by medications including diuretics and laxatives. Importantly incontinence predisposes to dehydration as people may limit their fluid intake.

Inadequate fluid intake is a major contributor to preventable dehydration. Poor oral intake of fluids can be related to the inability to feed independently and having poor availability and access to fluids. 

Consequences of dehydration

Dehydration is associated with poor health outcomes such as increased hospitalisation and mortality. For example, a two-fold increase in the mortality of stroke patients has been reported.

Even mild dehydration adversely affects mental performance and increases feelings of tiredness. Mental functions affected include memory, attention, concentration and reaction time.

Common complications associated with dehydration also include low blood pressure, weakness, dizziness and increased risk of falls.

Poorly hydrated individuals are more likely to develop pressure sores and skin conditions.

Water helps to keep the urinary tract and kidneys healthy. When fluid intake is reduced the risk of urinary tract infections increases. Inadequate hydration is one of the main causes of acute kidney injury.

Inadequate fluid intake is also one of the most common causes of constipation. In individuals who are not adequately hydrated, drinking more fluid can increase stool frequency and enhance the beneficial effect of fibre intake.

Many older people are reluctant to drink to avoid the need to go to the toilet, particularly at night, but restriction of overall fluid intake does not reduce urinary incontinence frequency or severity.

Signs of dehydration

Signs of dehydration include dryness of the mouth, lips and tongue, sunken eyes, dry inelastic skin, drowsiness, confusion or disorientation, dizziness and low blood pressure. Many of these signs are rather subjective and can present in other conditions.

Dehydration is also indicated with a reduced and more concentrated urine output. As a general rule, the colour of urine can be a useful guide; urine that is odourless and pale in colour generally indicates good hydration, dark strong smelling urine is a common symptom of dehydration. However, there are a number of medical conditions and certain medications that can add colour to urine.

Monitoring fluid intake is a good guide to ensuring good hydration.

What can be done to prevent dehydration in care settings?

Dehydration can be exacerbated in the residential care setting by lack of awareness of the importance of hydration and inadequate staff training. Recognising when the older person is not drinking enough and helping them to drink more and identifying the barriers to drinking, such as being worried about not reaching the toilet in time, physical inability to make or to reach drinks, and reduced social drinking and drinking pleasure is important.

There are a variety of potential ways to help older people reduce their risk of dehydration in care settings. These may include:

• staff training to recognise the importance of hydration.
• determine an individualised daily fluid intake goal
• provide preferred fluids
• have fluid available at all times
• make sure water is fresh and looks palatable — perhaps by adding a few slices of lemon or orange or ice cubes
• offer fluids regularly throughout the day

• offer fluids at routine events such as before physiotherapy or other activity or medication rounds
• offer a variety of hot and cold fluids

• provide assistance if required
• provide aids for drinking if needed such as special cups
• offer at least a full glass of fluid with medications
• encourage families and visitors to offer fluids
• encourage older people to eat wet foods such as

Medical and care staff and carers should be aware of the causes of dehydration in older people and understand how to maintain adequate hydration and to recognise the signs and symptoms of dehydration.

It is also important to recognise that Care Quality Commission Standards apply to hydration as well as nutrition and focus on identification and assessment, monitoring fluid intake and care. These include:

• Staff identify when a person is at risk of dehydration.
• Those identified as at risk have their fluid intake monitored.
• Hydration requirements are identified and reviewed and communicated.
• The care plan identifies how the risks will be managed.
• Patients can be confident staff will support them to safely meet their drinking needs.

Information reviewed August 2019