During the holy month of Ramadan, millions of Muslims fast from sunrise to sunset.
While it’s a deeply spiritual time, the long hours without food or water—especially in hot climates—can increase the risk of dehydration.
Now, scientists at KAUST (King Abdullah University of Science and Technology) have come up with a surprisingly simple way to help: using a smartphone screen.
The researchers discovered that the same kind of touchscreen technology used in everyday phones could be adapted to measure your hydration level.
By analyzing how a fingertip interacts with the screen, the system detects small changes in the skin’s ability to hold electric charge—something that shifts when you’re dehydrated.
Their findings, published in the IEEE Sensors Journal, open the door to an easy, real-time way to check your hydration status.
All it takes is a single touch—no blood tests, wearables, or complicated equipment.
With this method, your phone could potentially let you know when to drink water before you start feeling dizzy, tired, or faint.
The idea isn’t just for people who fast. The KAUST team, led by electrical engineer Tareq Al-Naffouri, also tested the approach on athletes who often lose a lot of fluids through sweat.
It could eventually help other groups too, like children, older adults, or people with kidney conditions, who are more prone to dehydration.
To prove it works, the team collected more than 4,000 fingertip readings from two main groups: people observing Ramadan and athletes playing ultimate Frisbee or exercising at the gym. Using machine learning, they trained a model to translate those skin readings into hydration data.
When tested, the system could correctly tell if someone was dehydrated with impressive accuracy—up to 92% for athletes and 87% for those fasting.
Study author Soumia Siyoucef, who helped lead the project, says the vision is simple: a world where anyone can just tap their phone screen to check if they need to hydrate.
As our phones continue to evolve, this kind of user-friendly health monitoring could soon be right at our fingertips—literally. Whether you’re fasting, working out, or just going about your day, a quick tap might be all it takes to stay safe and hydrated.
