The need to teach medical students plain language for their future engagement in pain communication can no longer be underestimated. Pain education has traditionally neglected the teaching of pain language, yet patients' descriptive accounts have been acknowledged as the standard in medical care. English for Medical Purposes (EMP) can make its contribution to tertiary pain education, especially at a time when the plain language paradigm is considered key for health literacy. This is not to say that teaching specialized language and plain language for specific purposes are mutually exclusive. Yet, developing EMP learners' understanding of the use of authentic plain pain language is also crucial for their future professional practice. This study reports on a pedagogical experiment conducted with the aim of enhancing EMP learners' understanding of the lexico-grammatical features of pain language in patients' descriptive accounts and in the use of pain assessment tools. The experiment was framed by the Hallidayan lexico-grammatical model of pain. Following a data-driven learning approach, students compiled a small DIY corpus of accounts from online health support groups and exploited its direct use through corpus-based tasks. These were designed to facilitate learners' understanding of the features of pain language and of patients' use of pain descriptors related to those in the McGill Pain assessment tool currently employed in medical care. Learners further broadened their understanding of pain language in other contexts of use while taking notes to fulfil the designed tasks. These helped shed light on the pedagogical practice here proposed.