Updating an ancient form of health diagnosis with modern machine learning, researchers have developed a remarkable system that can reveal a range of medical conditions just by looking at your tongue. Testing showed off its near perfect accuracy. Doctors have been asking to see your tongue for thousands of years.

And there's a very good reason for that. The color and condition of your tongue can actually reveal a great deal about what's going on in the rest of your body. While the technique seemed to take off in western medicine in the 17th century, it has actually been used in traditional Chinese medicine since around 1115.

Understanding the value of a good tongue analysis, researchers from from (MTU) in Iraq and the (UniSA) decided to see if they could standardize things a bit and bring more accuracy to the practice. They trained a machine learning system on 5,260 images of tongues taken in a wide variety of lighting conditions. They also fed it a series of images from individuals with known health conditions including asthma, diabetes, and anemia.

Then they tested the system by placing a camera 20 cm (7.8 in) from a patient's tongue and asked the system to form a diagnosis. It was correct 98% percent of the time, and it offered its results in real time.

“The color, shape and thickness of the tongue can reveal a litany of health conditions,” said MTU and UniSA professor Ali Al-Naji, who led the study. "Typically, people with diabetes have a yellow tongue; cancer patients.