Want to know if you're dehydrated? There's an app for that.

Some day soon, perhaps within the next 12 months, you will be able to attach a patch to your arm that tells you if you’re dehydrated.¹

You might be surprised that dehydration is even a cause for concern in a first world country like the UK, as for most people there is fairly easy access to clean drinking water. However, some people are often either unaware that they are dehydrated, or simply unable to hydrate themselves due to poor mobility or limited access.

A reduction in hydration levels of as little as 2% of body weight can lead to greater feelings of fatigue and reduced levels of alertness.²

The physical and financial cost of malnutrition and dehydration is a huge issue in the UK: More than 3 million people are affected at any one time, and the annual cost to the NHS associated with malnutrition exceeds £19.6 billion.³

Currently, the most accurate measurement of dehydration is a blood test. These are often relied upon in hospitals but are expensive and the time taken to get results limits their effectiveness. If a patient is dehydrated enough for it to show up in a blood test, the wait for the result is a delay they can’t afford.

Outside of a hospital setting, patients may be questioned on fluid intake and markers such as the quantity and colour of urine, dry mucus membranes, rapid pulse and slow capillary refill times are used to assess the extent of the problem.⁴ The questions are open to individuals’ interpretations though, and markers can be affected by underlying conditions and lifestyle, meaning both options can be inaccurate.

Fortunately, nearly everyone has access to water, and with visual and electronic indicators on phones or smartwatches, reminders and tracking apps that tell us what we should drink in a day, it should be relatively easy to stay hydrated. However, these are just guides to maintaining healthy levels of hydration, rather than assessing a person’s underlying biology. Plus, these technologies can only have an effect on the way we live our lives if we allow them to.

So, what is the future of tackling dehydration?

Devices are being developed that use patches to measure the chemical contents of sweat on the skin. These cheap, single-use skin monitors are wearable, wireless and battery-free and will analyse the sweat on your skin. This information will then link to an app to give the user the ability to monitor hydration levels and could even have the capacity to diagnose other health problems.

Expect companies like Apple and Fitbit are set to use sensors with similar capabilities and add this functionality to their smartwatches, alongside a host of start-ups developing cheaper wearable tech specifically designed to measure hydration.

Researchers at Harvard and MIT have developed bio sensitive inks. This “smart tattoo ink” incorporates biosensors directly onto the skin and can alert people to particular health characteristics such as dehydration and blood sugar levels by changing colour. ⁵

Technology like this has been anticipated for years, but recent development has accelerated quickly and intelligent tools will soon be at our fingertips.

I’m sure I’m not the only one who ignores the pop-up messages on phones and watches reminding me to take a break and rehydrate, instead choosing to remain glued to the computer screen. Ultimately, whatever technological advancements are available, they will be of little use unless we take an active role in improving our lifestyles.

References:

1. Mandavilli, A. (2019) ‘Your sweat will see you now’ The New York Times [online]. Available at https://www.nytimes.com/2019/01/18/health/wearable-tech-sweat.html. Accessed 23.9.19.

2. Powell, A. (2017) 'Researchers develop smart tattoo for monitoring' Phys Org [online]. Available at https://phys.org/news/2017-09-smart-tattoos-health.html . Accessed 23.9.19.

3. Marinos, E. (2015) 'The cost of malnutrition in England and potential cost savings from nutritional interventions' BAPEN [online]. Available at: https://www.bapen.org.uk/pdfs/economic-report-short.pdf.  Accessed 23.9.19.

4. Clinical signs of dehydration in older people: a diagnostic systematic review. Lee Hooper, Rowan A Needham, John F Potter, Paul Hunter (School of Medicine, University of East Anglia & Gateshead NHS Trust)

5. Derbyshire, E. (2016) 'Hydration in the workplace' National Hydration Council [online]. Available at: https://www.naturalhydrationcouncil.org.uk/wp-content/uploads/2016/07/NHC-Hydration-in-Workplace-fact-sheet-FINAL1.pdf. Accessed: 23.9.19.

Author: Paul Hayhow