CDC study links surge in hospital visits to cannabis hyperemesis syndrome with new coding

A CDC study finds a 16% rise in emergency department visits for cannabis hyperemesis syndrome after a dedicated diagnosis code was introduced, with nearly 200,000 visits from Jan 2023 through summer 2025. Increases were largest among 15–24-year-olds, teen girls and women, and among Black Americans and American Indian/Alaska Native groups, highlighting prior underdiagnosis and the need for more research on high-potency cannabis products and usage patterns.