Last reviewed 14 March 2019

Researchers from the University of East Anglia (UEA) have found that standard tests used in care homes to identify dehydration in residents do not work and should be withdrawn from practice.

The UEA study, which was funded by the National Institute for Health Research and published in the Journal of the American Medical Directors Association (JAMDA), showed the “gold standard” blood tests are much more accurate than the simple tests used by care workers in residential settings, such as asking residents if they feel thirsty, tired or have a headache, or looking at their eyes or skin.

UEA Norwich Medical School Lead Researcher Dr Lee Hooper explained: “Low-intake dehydration happens when people don’t drink enough fluids to stay healthy, and is very common in older people, including those living in care homes.

“It happens for all sorts of reasons, such as weakened thirst sensation, which happens as we age, not remembering to drink or difficulties fetching, carrying and reaching drinks.”

The simple tests are described as standard clinical indicators of dehydration and their use has been advocated in medical and nursing text books, care guidelines and health-related websites.

The study involved 188 men and women living in care homes in Norfolk and Suffolk, who underwent a number of standard dehydration tests such as looking in their mouth and feeling under their arm, having blood pressure, pulse and temperature measured, and answering questions about how they were feeling, including whether they felt thirsty or not.

They were also given a blood test for serum osmolality, which is the “gold standard” test for measuring low-intake dehydration.

Comparing all the other tests to the “gold standard” found that none of the standard simple tests accurately identified people with dehydration.

UEA School of Health Sciences Lead Author Dr Diane Bunn said: “Whilst blood tests are the most accurate way of telling if someone is dehydrated, this is expensive and not easily done in care homes unless a doctor orders the test. We really need an inexpensive easy-to-do test for dehydration in older people, and one which works.”

The study, Signs and Symptoms of Low-intake Dehydration Do Not Work in Older Care Home Residents — DRIE Diagnostic Accuracy Study, is available at