Young people are being admitted to emergency rooms for a severe vomiting disorder linked to cannabis use.

The disorder, known as cannabinoid hyperemesis syndrome (CHS), surged by more than 650 percent between 2016 and 2022, according to a study.

In the first quarter of 2020, CHS cases jumped from 4.4 per 100,000 emergency visits to a peak of 33.1 per 100,000 visits in the second quarter of 2020. Although numbers declined slightly afterward, they remained elevated at 22.3 per 100,000 visits in 2022.

“CHS is definitely common and is one of the leading causes of recurrent nausea and vomiting in young adults,” Dr. Gautham Oroskar, a board-certified internal medicine physician and medical adviser at Kazmira Therapeutics, who was not involved in the study, told The Epoch Times.

“It is usually seen in heavy, chronic marijuana users.”

Men and Younger Adults Face Higher Risk

For this study, published in JAMA Network Open, researchers analyzed data from more than 188 million emergency visits across the United States, covering patients aged 12 and older from roughly 85 percent of U.S. emergency visits. Patients who were pregnant or who had gastroparesis or chemotherapy-related visits were excluded.

Young adults aged 18 to 25 faced the highest risk: They were about 260 percent more likely to develop CHS than other age groups. Those aged 26 to 35 were roughly 125 percent more likely. Males had a slightly higher risk than females.

“Most patients [with CHS] I see in the clinic now are between 18 and 50 years old,” Dr. John Dumot, a gastroenterologist and clinical assistant professor of medicine at Case Western Reserve University, who was not involved in the study, told The Epoch Times.

Researchers still do not know why cannabis use causes a vomiting disorder, and it’s possible that some of the cases were misdiagnosed and caused by other gastrointestinal issues. However, the syndrome is linked to long-term marijuana use.

The researchers pointed to greater access to cannabis as a likely driver for the increased cases, with nearly half of all U.S. residents now living in states where recreational cannabis is legal.

Oroskar said he believes that the prevalence of CHS has increased because of the high-potency marijuana products currently on the market.

“This is not a CBD thing,” he said. “It’s a THC thing.”

However, the mechanism by which THC causes the condition remains unclear.

Dumot said a history of chronic cannabis or THC product use is critical to the diagnosis.

“The longer the use and the higher the dose, the higher the risk of CHS,” he said.

Most CBD products contain small amounts of THC because of the extraction process, Oroskar said, and that THC content may trigger CHS in some people.

Dumot said the condition is “somewhat paradoxical” because many patients report temporary relief from nausea after using cannabis or THC products. However, he added, “the symptoms of nausea and vomiting recur as the drug levels wane.”

Researchers said their report may have overstated case numbers because it tracked hospital visits rather than individual patients. In addition, because there was no diagnostic code for CHS until 2025, the researchers identified earlier cases based on symptom patterns consistent with the condition.

In a commentary published alongside the study, Dr. Michael Gottlieb, an immunologist, and colleagues suggest that the increase in visits may also reflect improved recognition of CHS by health care providers and patients, leading to earlier and more accurate diagnoses.

Treatment Remains Challenging

Stopping cannabis use will prevent CHS, according to Gottlieb, but abrupt discontinuation could lead to withdrawal symptoms and relapse.

Traditional anti-nausea medications often don’t work well for CHS. However, emerging evidence suggests that atypical antipsychotics such as olanzapine may help and early research indicates that regional anesthesia might be another treatment option, Gottlieb said.

Dumot noted that two treatments can be particularly helpful.

“For mild cases, capsaicin cream can be applied to the upper abdomen for relief,” he said. Capsaicin cream, which contains a compound found in chili peppers, causes a sensation of heat that can relieve pain when used topically on the abdominal area, but it may not be tolerated well by all patients.

“More severe cases benefit from judicious use of olanzapine, which is an antipsychotic medicine that is taken usually at night,” Dumot said.