Cannabinoid hyperemesis syndrome prevalence studied

A University of Illinois study looking at cannabinoid hyperemesis syndrome (CHS) presentations in US emergency departments has revealed some interesting/disturbing results.

Cannabinoid hyperemesis syndrome, also known as ‘scromiting‘ is a condition in some chronic and heavy users characterised by recurrent nausea, vomiting and abdominal pain. It may also be accompanied by loud vocalisations during vomiting; hence the term scromiting — screaming + vomiting.

With legal cannabis in some form accessible in most US states — nearly half of all US residents lived in states with legalized recreational cannabis in June 2025, and approximately three-quarters of the population live in a state with a medical cannabis program — it would be fair to assuming prevalence CHS is increasing too.

Is it really?

The new study assessing trends from 2016 to 2022 in hospital emergency departments found CHS increased from 4.4 per 100 000 visits, peaked at 33.1 in quarter 2 2020, and remained elevated at 22.3 in 2022. The sample for the analytic study included 188.610.906 visits that were not weighted (806 millions if they had been).

The authors state that the peak is expected to be in 2020.

COVID-19 likely contributed to the CHS rise through increased stress, cannabis use, and isolation. CHS was at its highest in 2021. After that, it declined, but plateaued over prepandemic levels. This suggests sustained structural or medical drivers.

CHS patients were overrepresented in the age ranges of 18 to 25 (35.7%) and from 26 to 35 (31.5%).

The authors conclude by stating:

These findings underscore the need to continue vigilance, and refine the clinical diagnosis of CHS.

Study paper has been published Jama Network Open : Emergency Medicine

Among the limitations of the study, CHS was not directly coded in ICD-10* during the study period, so proxy definitions were used that raised misclassification risk. While cannabis usage may not have been reported in some cases, other symptoms may have led to misclassification.

Just to mention that in July, an American instructor of medicine expressed concern about CHS being diagnosed incorrectly too frequently without the proper diagnostic evaluation.

Trivia: Cannabinoid Hyperemesis Syndrome was discovered for the first time in Australia in 2004.

*The International Statistical Classification of Diseases and Related Health Problems, 10th Revision (ICD-10It is an international system of coding for diseases, injuries and other conditions.