New Study: 85% of CHS Patients End Up in the ER and Most Never Connect It to Their Cannabis Use

One of the first large-scale studies to quantify the real-world burden of cannabinoid hyperemesis syndrome has found that the condition drives the vast majority of sufferers into emergency rooms — and nearly half into full hospitalizations — often repeatedly, over years.

The research, led by Andrew Meltzer, professor of emergency medicine at the George Washington University School of Medicine & Health Sciences, surveyed 1,052 individuals who reported experiencing CHS. Published and highlighted by Respiratory Therapy magazine on February 26, 2025, the findings paint a sobering picture of a condition that is quietly generating enormous clinical and economic cost.

“This is one of the first large studies to examine the disease burden associated with this cannabis-linked syndrome,” said Meltzer. “Our findings suggest that cannabinoid hyperemesis syndrome could represent a costly and largely hidden public health problem.”

A pattern of heavy, long-term use

CHS develops in people who consume cannabis regularly over extended periods, producing recurring cycles of severe nausea, uncontrollable vomiting, and intense abdominal cramping that drive patients back to the hospital again and again. While emergency physicians can manage the acute crisis — stabilizing patients and easing the worst of the symptoms — the only intervention that actually stops the episodes is complete cessation of cannabis use.

The study’s data on usage patterns were striking. Daily cannabis consumption before the onset of the syndrome was essentially universal among respondents. More than 40% reported using marijuana upward of five times per day, and 44% had been using regularly for over five years before CHS symptoms first appeared. Early initiation of cannabis use was also identified as a risk factor: the younger a person started, the higher their odds of eventually needing emergency care.

The healthcare toll: by the numbers

The survey results leave little ambiguity about how heavily CHS burdens both patients and the healthcare system:

• 85% of respondents reported at least one emergency department visit related to their CHS symptoms.
• 44% had been hospitalized at least once due to the condition.
• For many, these were not isolated events — repeated visits are the norm, not the exception.

Each trip to the ER involves costs: medical fees, lost work time, transportation, and the physical toll of hours or days spent in severe pain. Multiplied across a population of millions — exact prevalence remains unknown, but experts broadly agree the condition is becoming more common as daily cannabis use rises across the United States — those costs add up quickly.

A syndrome hiding in plain sight

One of the most consistent and troubling findings across CHS research — including this study — is how rarely patients connect their symptoms to their cannabis use. The drug has long carried an association with nausea relief, particularly in oncology settings where it has been used to help manage chemotherapy-induced vomiting. The idea that the same substance could be causing the vomiting runs contrary to what most users have been told or come to believe.

Meltzer emphasizes that closing this knowledge gap is a clinical responsibility. “It is important for clinicians to advise those with frequent cannabinoid use or hyperemesis about the risks and subsequent disease burden,” he says. “Many patients don’t realize that the syndrome is connected with their cannabis use. Physicians should explain that and advise patients on resources to help them quit.”

The message for patients is the same as it has been since CHS was first identified: the emergency room can manage the crisis, but it cannot resolve the condition. Only stopping cannabis use entirely — across all delivery methods — achieves that. For a population of daily or near-daily users, that is a significant ask. But according to the evidence, it is the only one that works.

Source: “Daily Cannabis Use Linked to Syndrome, Hospitalizations,” Respiratory Therapy, February 26, 2025. Study led by Andrew Meltzer, MD, George Washington University School of Medicine & Health Sciences.