ER visits for cannabis hyperemesis syndrome in Canada rose 13-fold, prompting a class action and growing calls for clearer CHS warnings on cannabis products.
Sharp Rise in Severe Vomiting Cases
Emergency‑department data show 12,866 visits for cannabis hyperemesis syndrome (CHS) in Ontario between 2014 and 2021—a 13‑fold jump that accelerated after retail expansion in 2020.
Daily Smoker’s Ordeal Illustrates Toll
Operations trainer Brittany Ramsey, 35, says a decade of once‑daily smoking left her hospitalised 29 times with relentless vomiting that only hot showers eased. Her three‑year search for answers ended with a CHS diagnosis in 2024, underscoring how easily the syndrome is missed.
Potency and Retail Expansion Under Scrutiny
Researchers link the surge to today’s far stronger products—average THC content has climbed from 3 % in the 1980s to about 15 %, with some dried strains hitting 30 % and concentrates reaching 90 %. Greater store access since 2020 likely magnified exposure.
Class Action Targets Aurora Cannabis
On 14 May 2025 the Ontario Superior Court certified a national lawsuit alleging Aurora Cannabis failed to warn consumers about CHS risks. The case could force industry‑wide label changes if successful, lawyers say.
Experts Press for Better Warnings
Western University epidemiologist Jamie Seabrook notes an “explosion” of CHS presentations in the past decade and urges schools, hospitals and public‑health campaigns to flag the danger so users can make informed choices.
Health Canada already mandates labels on psychosis and dependence. Advocates want CHS added, along with frontline‑clinician training and consumer education. Federal officials have not said when—or if—rule changes will occur, but the lawsuit and mounting ER data keep the issue in the national spotlight.