A Cardiff University student carrying out research into fatal diseases found many of the medical terms did not exist in his mother tongue.
But far from being dissuaded, Bedwyr Ab Ion Thomas decided to make up Welsh words to explain his studies.
The 23-year-old now hopes to have made a mini dictionary of new terms to help others by the time he finishes his PhD.
"I hope that I can contribute not only to science but also to the Welsh language," he said.
The medicinal chemistry student from Cardiff is attempting to develop treatments for rare diseases, such as mad cow disease, kuru and Creutzfeldt-Jakob disease (CJD), for which there are currently no cures.
But carrying out his research in Welsh has brought up some "extra challenges", with many of the scientific terms used only existing in English or Latin.
One example is a binding pocket - where a drug would bind in a protein - which he translates as "poced feindio".
"These inconsistencies emphasise the need for scientific terms in Welsh to be standardised to avoid confusion," he said.
"Being able to live, study and work through the medium of Welsh in Wales should be the norm and my hope is that many others will also see this as a great start to their career."
Professor Simon Ward, director at the university's Medicines Discovery Institute, said it was "important" to show you could study any topic in Welsh.
"You don't just have to be studying Welsh poetry in the Middle Ages - you can also do cutting-edge scientific research," he said.
Dr Dylan Phillips, senior academic manager at the Coleg Cymraeg Cenedlaethol, said Welsh medium expertise needed to be developed in the sciences to create the "next generation of Welsh-medium lecturers and researchers".