Marijuana-Induced Vomiting Syndrome Rising in Young Men

Remember that stoner friend from your 20s who raved about the wonders of weed? In an almost ubiquitous experience, the sage stoner will tell friends the worst that can happen from excessive smoking is paranoia or wanting to melt into a couch with a mound of snacks.

But recent studies show about 2.75 million people in the United States — mostly men between 16 and 34 — suffer from a form of cyclical vomiting called cannabinoid hyperemesis syndrome (CHS). Yale University professor and director of the Yale Center for the Science of Cannabis and Cannabinoids Dr. Deepak D'Souza tells New Times the gastrointestinal condition, which causes severe nausea, bouts of vomiting, and intense abdominal pain, has been sending young men to emergency rooms nationwide. Doctors agree the main cause is excessive smoking.

According to a 2024 study by University of Illinois doctors examining CHS in the pediatric population, the symptoms often appear seemingly without warning, even for those with no significant past medical history.

A 2022 study published in the Journal of the American Medical Association found the legalization of marijuana in Ontario, Canada, led to a 13-fold increase in the number of emergency department visits for patients with CHS over a seven-year period. Researchers in the U.S., in states where marijuana is legal, are finding similarly troubling trends, D'Souza says.

In January 2014, about four years before Canada legalized marijuana, there were an average of 0.26 CHS emergency department visits per 100,000 people; that number grew to 3.40 visits per 100,000 by June 2021. And while 51 percent of patients studied in Canada were women, doctors in the U.S. are overwhelmingly seeing more male patients, D'Souza says.

"It could be as simple as men smoking more cannabis, but I think the really heavy cannabis users tend to be represented more by males," D'Souza says.

The Canadian study linked legalization to the sharp increase in CHS-related emergency visit rates but notes that more research is needed to further prove the link between legalization and commercialization of cannabis and the rise in CHS.

Those with the highest risk of developing CHS are excessive smokers, which doctors define as those who partake in daily or near-daily use of cannabis.

Before the disorder was first identified in 2004, patients would come to emergency rooms with stomach issues that were difficult for doctors to diagnose, D'Souza says. Marijuana was illegal nationwide at the time, and the War on Drugs made the stigma surrounding the plant strong enough to keep many smokers from being honest about their habit.

Stigma notwithstanding, doctors had their own preconceived notions about marijuana.

"For a long time, the medical community thought about cannabis as an anti-nausea medication," D'Souza says. "So, because that was such a large part of our mindset, it might have been hard for us to recognize."

According to a 2017 University of Kentucky study, the first documented case of the disorder occurred in 2004, when a 45-year-old man with severe nausea and bouts of vomiting made repeated hospital visits. Even after 11 visits for the same issues over eight years, doctors weren't sure how to diagnose the patient until he mentioned that he had begun smoking marijuana again shortly before the most recent bout.

Researchers then learned that the man had gone 20 months with no symptoms until he took up smoking again, leading them to the only known cure for CHS: Stop smoking. "Returning to marijuana use often results in the returning of CHS," the study notes.

Quitting cold turkey, however, can lead to withdrawal symptoms and relapses, so doctors advise visiting a psychologist or psychiatrist for help.

"Unfortunately, we don't have any good medication or treatments for someone who is addicted to cannabis," D'Souza tells New Times. "But when someone stops abruptly, they may feel cannabis withdrawal symptoms. So, the best option is to seek a clinic with a psychiatrist or psychologist and resources to help."

While not every CHS case is created equal, researchers agree most can be divided into three phases: prodromal, hyperemesis, and recovery. The University of Kentucky study defined prodromal CHS as early-morning nausea and abdominal discomfort. Ironically, many patients experience that discomfort and think the solution is smoking more marijuana, which can subdue those same issues in a person without CHS, D'Souza says.

The second stage, hyperemesis, is when people typically go to the hospital with severe stomach pain and bouts of vomiting. Standard medications used to treat those symptoms are often ineffective for CHS patients, making it crucial for individuals to be upfront with doctors about their cannabis use, D'Souza says.

The final phase, recovery, is a return to normal, which can take weeks or months and continues as long as the patient refrains from using cannabis.

"If patients continue to use marijuana, they often have recurrence of the hyperemesis phase," the University of Kentucky study found.

Precisely how exactly CHS affects patients long-term remains something of a mystery because the disorder was discovered so recently. What researchers do know is some patients' CHS vomiting is so severe it leads to erosion of tooth enamel and, eventually, tooth loss. In rare cases, patients have suffered heart rhythm abnormalities, seizures, kidney failure, and death.