CHARLOTTESVILLE, VA (CVILLE RIGHT NOW) – A new data analysis by the Virginia Hospital and Healthcare Association shows annual adult visits to emergency rooms due to cannabis use, dependence, and poisoning increased 29% from 2020 until 2024.

Cannabis was decriminalized in Virginia in 2020, then possession of less than an ounce was legalized in July 2021.

The VHHA survey shows there were 4,027 ER visits in cases that were diagnosed as cannabinoid hyperemesis syndrome (CHS) in 2020, and that number increased to 5,175 in 2024.

“The symptoms include recurring episodes of severe nausea, abdominal pain, and vomiting,” VHHA Vice President of Communications Julian Walker told Cville Right Now.

Walker said little comparative data exists from before 2020.

“Certainly seeing more frequently in the emergency department, and early in my career at the University of Virginia you never saw that disorder,” Dr. Christopher Holstege, Professor of Emergency Medicine at UVA School of Medicine and the Director of the Blue Ridge Poison Center told Cville Right Now. “It wasn’t until, I would say, that they started starting approaching decriminalization, and certainly afterwards, that we started Cville’s cases coming in.”

Both Walker and Holstege point out academic research focusing outside of Virginia has also documented rising CHS cases leading to emergency department visits.

Walker offered a study recently published in the Journal of the American Medical Association evaluated CHS trends in U.S. hospital emergency departments from 2016-2022 and found that “CHS visits clustered among adults aged 18 to 35 years, rose during the COVID-19 pandemic from 2020 to 2021, then plateaued. Among ED visits with primary cyclic vomiting syndrome, the conditional probability of CHS remained elevated in 2022.”

Another study published in 2024 by the International Society of Addiction Journal found a sharp increase in hospital emergency department patients in Northern California over an 11-year period from 2009-2019. Based on a review of electronic medical records, the research showed that 57,277 adult patients had a CHS-related hospital emergency department visit over that time. The study authors found that “annual prevalence increased by 134 percent” for such CHS cases.

The Internal Medicine Journal published a study in 2019 that showed a 46 percent increase in Colorado hospitalizations from 2010-2014 for cyclic vomiting syndrome (CVS) due to cannabis use.

And a recent George Washington University study of patients who reported experiencing CHS found that 85 percent reported at least one emergency department visit and 44 percent reported at least one hospitalization associated with hyperemesis symptoms.

“Each of these studies presenting similar conclusions which is there has been a rise in these cases of abdominal distress, of cyclic vomiting associated with long-term consistent cannabis use,”  Walker said.

Dr. Holstege said the syndrome is not observed just among occasional cannabis use, “It’s not with someone who does one smoke of cannabis and then doesn’t do it again for a week.”

“These are people who tend to use it more frequently… and patients who I’ve seen in the past just find it hard to believe that’s what’s causing it, they think that cannabis helps it.”

As far as how dangerous the syndrome is, Dr. Holstege said, “For most people who are healthy, I don’t know of anyone who has died from it, but it’s miserable to have it.”

Dr. Holstege said sufferers have expressed some different methods of symptom relief.

“One of the things that unique with that syndrome is the nausea and vomiting is relieved by going to the shower, the warmth of the shower actually helps to alleviate it,” Dr. Holstege reported. “Or using something like IcyHot has been talked about, too, because of those receptors on our body.”

In conducting this analysis, VHHA release said they examined all-payer emergency department and hospital discharge data for calendar years 2020–2024. To identify CHS cases, VHHA conducted a search for records containing CHS codes as well as those involving patient encounters with cyclical or non-specific vomiting plus cannabis-related diagnoses in a manner consistent with the parameters of this reference study. Data on patient encounters that contained at least one ICD-10 diagnosis code indicating cannabis abuse, dependence, or related poisoning were included in the analysis of total such visits.