A unique vomiting disorder linked to long-term cannabis use is increasingly appearing in emergency rooms across the United States.
This condition, known as cannabinoid hyperemesis syndrome (CHS), is characterized by intense and recurring episodes of nausea, abdominal discomfort, and vomiting.
The first documented case in the US was noted in 2009, but until recently, CHS lacked a national diagnostic code, which complicated tracking efforts.
Visits to the ER represent one of the few ways to gauge the prevalence and causes of this syndrome.
A study conducted by researchers at the University of Illinois Chicago revealed that from 2016 to 2022, the number of CHS-related emergency visits surged from about 4 instances per 100,000 to 22 per 100,000.
Related: Cannabis Use Is Linked to Epigenetic Changes, Scientists Discovered
Although CHS remains relatively uncommon, this trend is worth monitoring. Notably, symptoms can be alleviated with appropriate interventions.
It’s important to note that frequent cannabis use doesn’t guarantee the development of CHS. The reasons why it affects only a minority of users are still unclear, though it tends to occur more often in younger individuals.
Typically, the syndrome manifests gradually in the first few years of use, often beginning with morning nausea or stomach pain, and can persist for an extended time.
The intense phase follows, where individuals experience severe vomiting and nausea for a day or two after using cannabis.
Interestingly, some people find that taking a hot bath or shower can temporarily ease these distressing symptoms.
Ceasing cannabis use can resolve the syndrome.
Amid the COVID-19 pandemic from 2020 to 2021, researchers James Swartz and Dana Franceschini observed a notable uptick in CHS cases in US emergency rooms.
Their examination included approximately 806 million ER visits over the six-year period, marking it as the third national study on CHS trends in the country.
Most hospital visits for CHS came from individuals around 30 years old, with a slightly higher incidence in females than males. The condition seemed more prevalent in the West and Northeast than in the South.
It’s unclear whether this increase is due to heightened cannabis consumption or simply greater awareness of CHS.
Swartz and Franceschini propose that the COVID-19 pandemic might have triggered the recent rise in cases due to factors such as stress and isolation, along with increased cannabis usage.
However, other researchers argue that the higher diagnosis rates may not correlate to an actual rise in cannabis consumption.
Instead, it might reflect better recognition of CHS and a publication bias towards this newly acknowledged syndrome.
Historically, CHS has been depicted as “rare but significant” and often misunderstood, with some patients enduring up to 17 hospital visits before getting a proper diagnosis. Additionally, a few have been accused of exaggerating their symptoms.
When someone arrives at the hospital with CHS-like symptoms, doctors must diagnose it through a process of elimination after discarding other potential causes.
Interestingly, CHS is frequently misidentified as cyclic vomiting syndrome, which requires different treatment. Cannabis use is crucial in narrowing down the diagnosis, yet some doctors might not consider it, and some patients may hesitate to disclose their usage.
Swartz and Franceschini note, “The absence of a clear rise in CHS prior to 2020, despite the expanding legalization of cannabis and greater availability of high-potency products, is perplexing.”
They suggest one possible explanation could be underdiagnosis or misclassification prior to CHS receiving wider clinical acknowledgment. The surge since 2020, they argue, may indicate both greater exposure and enhanced diagnostic attention.
Improved diagnostic methods and further research are necessary to truly understand how rare CHS is.
The findings were published in JAMA Network Open.
