The secrets of a mysterious 2,000-year-old papyrus have finally been revealed after years of research to solve the riddle of the strange document. The strange artifact, which has mirror writing on both sides, has been in the possession of the University of Basel in Switzerland since the 16th century.

Written in ancient Greek reportedly by an influential Roman doctor called Galen, the medical text refers to a condition known as "hysterical apnea," which describes how sex-starved women become hysterical.

"This is a sensational discovery," said Sabine Huebner, professor of ancient history at the University of Basel, in a statement. "The majority of papyri are documents such as letters, contracts and receipts. This is a literary text, however, and they are vastly more valuable."

“We can now say that it’s a medical text from late antiquity that describes the phenomenon of ‘hysterical apnea’,” says Huebner. “We therefore assume that it is either a text from the Roman physician Galen, or an unknown commentary on his work.”

Now University of Basel experts, using infrared and ultraviolet scans, believe the Greek-language papyri are a medical text, likely written by an influential Roman doctor called Galen.

Huebner cracked the text after working on it for three years with an interdisciplinary team in collaboration with the University of Basel’s Digital Humanities Lab. The papyrus collection has been digitized, transcribed, annotated and translated.

The discovery was made during an editing project funded by the Swiss National Science Foundation.

"The papyri are all part of a larger context. People mentioned in a Basel papyrus text may appear again in other papyri, housed for example in Strasbourg, London, Berlin or other locations. It is digital opportunities that enable us to put these mosaic pieces together again to form a larger picture," Huebner said.

In a 2012 paper on female hysteria, a team of researchers from the University of Cagliari wrote Galen embraced similar views to those of Hippocrates -- widely considered the father of medicine who was the first to coin the term “hysteria.”

Feminist scholar and neurophysiologist Ruth Beier said, according to Smithsonian, that Hippocrates believed hysteria was triggered by movement of the “‘wandering womb,’ a uterus that has become too dry, usually from lack of coitus. … Such an unhappy uterus bumps around in the abdomen, looking for moisture and, when it hits the liver, may produce sudden suffocation.” Beier added that ”[t]his was known, reasonably enough, as hysterical apnea.”

University of Basel The logo is seen at the University of Basel in Basel, Switzerland March 29, 2017. Photo: Reuters/Arnd Wiegmann