What frequent cannabis use may reveal about CHS warning signs

Cannabinoid hyperemesis syndrome (CHS) is increasingly being observed in emergency departments and is characterized by recurrent nausea and vomiting in some cannabis users. Despite its increasing prevalence, tools for early identification and intervention are lacking. This study aimed to improve our understanding of CHS by examining patterns of cannabis use and identifying symptom profiles of individuals suspected or diagnosed with CHS. By identifying the risk factors and initial warning signs, we can support earlier recognition, harm reduction, and intervention. An anonymous survey was distributed via social media to gather detailed, self-reported information about cannabis consumption methods, frequency of use, product sourcing, and CHS-related symptoms. Participants were recruited online through organic outreach to CHS-focused social media communities in late 2024. A total of 1134 participants were included in the final analysis. Most respondents reported smoking cannabis flower or using vape cartridges, although the use of edibles and concentrates were also described. The overwhelming majority of respondents (96.5%) used cannabis products at least daily, with approximately half (45%) using them six or more times per day around the time they developed CHS symptoms. Most of the respondents (61.9%) sourced cannabis from licensed dispensaries. The duration of cannabis use prior to symptom onset varied widely among participants, with nearly two-thirds (65.4%) reportedly used for more than 3 years before symptom development. During the prodromal (early) phase, symptoms clustered in the morning (63.1%) and the predominant complaints were nausea and stomach pain. Women reported more frequent and prolonged symptoms than men. Our findings suggest that CHS is most associated with long-term, frequent use of inhaled delta-9-tetrahydrocannabinol (Δ9-THC) dominant cannabis. The acquisition source of cannabis products did not affect the syndrome presentation. Although many different cannabis consumption methods were represented, smoking and vape cartridges were the most commonly reported. The use of vape cartridges was associated with a shorter time to the development of CHS symptoms. Increased awareness of these patterns could improve the early recognition and management of CHS.