With spots, rashes and a sudden lack of colour being some of the most basic signs of illness, we often look to the skin for clues about our health.

Now, scientists at Harvard and MIT are taking this process to the next level with the development of a new breed of smart tattoo that is capable of tracking the body’s internal processes.

By replacing traditional tattoo ink with a biologically sensitive alternative, researchers have created a form of body art that changes colour to represent key health indicators like dehydration or a drop in blood glucose levels.

For those with chronic conditions like diabetes, these tattoos could mark the end of problematic personal monitors that are dependant on batteries and wireless forms of connectivity.

And, unlike existing tattoos, these skin based health trackers don’t have to be permanent or visible. Experts believe that with enough refinement they will be able to put a time limit on each tattoo’s existence or make them viewable only under certain types of light.