Cannabis may offer relaxation, pain relief, and recreational enjoyment for millions of Americans, but new research suggests that long-term use can come with an unsettling side effect. A recent study released this week reports a steady rise in emergency room visits related to a condition known as cannabinoid hyperemesis syndrome (CHS), a disorder marked by severe nausea, stomach pain, and uncontrollable vomiting.
The study, conducted by researchers at the University of Illinois Chicago, examined data from emergency departments across the United States. Their findings show that suspected CHS cases have grown significantly since the late 2010s, with young adults making up a large portion of the increase. The condition is not new, but the researchers say it is becoming a more recognisable — and more frequently encountered — problem for emergency physicians.
“Cannabinoid hyperemesis syndrome is real, and we’re seeing it more often in ER settings,” said lead author James Swartz of UIC’s Jane Addams College of Social Work.
People experiencing CHS endure waves of intense abdominal cramps and repeated vomiting episodes that can last up to two days. The pain can be so overwhelming that patients cry out or scream while vomiting — a disturbing combination that has been informally dubbed “scromiting.”
CHS tends to appear in individuals who have used cannabis heavily over many years. Scientists still don’t fully understand what triggers it, though one theory suggests that constant exposure to THC may overstimulate cannabinoid receptors in the digestive system. While the syndrome has long been considered rare, reports have increased in places where cannabis use has become more widespread.
For this study, researchers reviewed ER data from 2016 to 2022. Because CHS only recently received its own medical classification, the team looked instead for cases where a patient was diagnosed with both cannabis use and cyclical vomiting syndrome — a combination used as a stand-in for CHS.
Over the six-year period, roughly 100,000 such cases were identified nationwide. Before the COVID-19 pandemic, yearly rates were relatively stable. But starting in 2020, suspected CHS cases rose sharply, peaking in 2021 before dipping slightly in 2022 — though still remaining higher than pre-pandemic levels. Notably, vomiting cases unrelated to cannabis did not increase, reinforcing the likelihood of a real rise in CHS occurrences.
The findings were published in JAMA Network Open. The researchers believe several factors likely contributed. The pandemic brought heightened stress, isolation, and increased cannabis use, which may have accelerated the trend. At the same time, expanding legalization and higher THC concentrations in modern cannabis products may also be driving forces.
While CHS can be frightening, it is treatable. Many patients find temporary relief from hot showers or baths during an episode, though the only reliable long-term solution is to stop using cannabis entirely. Symptoms typically fade over several weeks.
Despite the upward trend, CHS remains uncommon overall. Still, the authors stress that healthcare providers must become familiar with the condition now that it has been formally added to the International Classification of Diseases, making diagnosis easier.
“Cannabis isn’t harmless, especially with heavy or prolonged use,” Swartz noted. “Greater clinical awareness is essential so patients can get proper care without unnecessary testing.”
