Cannabis Hyperemesis Syndrome: Diagnosis and Care in the Emergency Department.

The recreational use of cannabis is a significant (and growing) contemporary public health issue, confounded by the rapidly changing state and federal marijuana regulation and legislation. As of 2025, 24 states and the District of Columbia have legalized cannabis for medicinal and recreational use, and 39 of the 50 states have legalized it for medicinal use. With the increased use of recreational and medicinal marijuana, there has been an uptick in emergency department (ED) visits for cannabis-related illnesses, including gastrointestinal, cardiac, and mental health disorders. Nausea and vomiting, which are the hallmarks of cannabinoid hyperemesis syndrome (CHS), have been reported as the most common reasons for cannabis-related ED visits in nationwide ED data set analysis. Emergency department staff need to be familiar with CHS, its presentation, pathophysiology, and treatments to quickly recognize, diagnose, and triage/treat patients suffering from this acute cannabis-related GI illness.