Between September and October 2025, the recorded rate of a particular cannabis-related condition jumped from 3.35 per 10,000 ER visits to 11.26 per 10,000 – nearly a fourfold increase in a single month. No outbreak was declared. No new drug hit the market. The number climbed again to 13.10 per 10,000 by May 2026, and the condition behind those visits has earned one of the more viscerally descriptive nicknames in modern medicine: “scromiting.”
The word is a portmanteau of screaming and vomiting, and it describes exactly what happens. Cannabis hyperemesis syndrome (CHS) is a condition characterized by cyclical nausea and vomiting associated with frequent cannabis use. During the worst episodes, CHS causes recurring bouts of severe stomach pain, nausea, and vomiting, with retching striking up to four or five times an hour. For people going through it, the pain is severe enough to send them straight to the emergency room – sometimes repeatedly, over months or years, before anyone correctly identifies what’s causing it.
A nearly 400% increase in CHS-related ER visits sounds like a crisis. Much of the spike, however, traces to a single administrative change: the introduction of a dedicated diagnosis code that finally gave clinicians a reliable way to count the condition.
The Coding Change That Changed Everything
A new CHS-specific ICD-10-CM diagnosis code – R11.16 – became effective on October 1, 2025. Before that date, CHS did not have its own ICD code. Doctors had to combine a separate code for cyclical vomiting with a code indicating cannabis use, a workaround that was almost guaranteed to miss cases, misclassify them, or bury them under catch-all diagnostic categories.
During January 2023 through May 2026, nearly 200,000 ED visits involved CHS. During January 2023 through September 2025, the proportion of ED visits that involved CHS remained largely steady. In the first month after implementation of the new diagnostic code, the proportion of CHS-involved ED visits increased from 3.35 per 10,000 in September 2025 to 11.26 per 10,000 in October 2025.
CHS-involved ED visits barely moved for nearly three years before the new code took effect – ranging from 3.19 per 10,000 in January 2023 to 3.35 by September 2025, never straying outside a narrow band. The moment the dedicated code went live, the numbers tripled. During the first eight months after implementation – October 2025 through May 2026 – average monthly proportions of CHS-involved ED visits were 3.7 times as high as the monthly average during January 2023 through September 2025.
The CDC noted that this abrupt, sustained increase might partly reflect improved recognition and coding of CHS rather than a true rise in incidence. The cases that were always there are now being counted.
What CHS Actually Does to the Body
CHS is not a passing bout of nausea. The vomiting can be relentless and unresponsive to standard anti-nausea medications, which is one of the reasons people with the condition so often end up in the ER. Early warning signs, such as morning nausea, may appear well before severe vomiting episodes begin.
One of the most unusual features of the syndrome is how some sufferers manage temporary relief: compulsive hot bathing or showering. The behavior is so consistent among CHS patients that clinicians often use it as a diagnostic clue.
Left untreated or misidentified, the physical consequences compound quickly. During the early phase of CHS, symptoms cluster in the morning, with nausea and stomach pain as the predominant complaints. As episodes escalate, the uncontrollable vomiting can produce dangerous downstream effects, including acute kidney injury, electrolyte imbalances, dehydration, and in the most serious cases, seizures.
The only known way to resolve CHS is stopping cannabis use entirely. That fact – combined with how deeply embedded daily use tends to be among those affected – explains why repeat ER visits are so common.
Who Gets It, and How Quickly
The demographic patterns in the CDC’s surveillance data are striking. Higher proportions of CHS-involved ED visits were observed among persons aged 15 to 24 years and females, with more pronounced impacts among some demographic groups after code implementation.
The timeline of symptom onset is shifting, too. CHS was once considered a disorder that only developed after years – sometimes a decade or more – of heavy daily use. Emerging evidence cited by CDC researchers suggests symptoms can occur much sooner than previously estimated, potentially within the first year of cannabis use. A California study surveying more than 1,130 CHS patients found that nearly two-thirds had used cannabis for more than three years before symptoms developed, but a meaningful minority developed CHS much faster.
The overwhelming majority of survey respondents – 96.5% – used cannabis products at least daily, with approximately half using them six or more times per day around the time they developed CHS symptoms. Frequency of use, more than duration, appears to be a critical factor.
Why Vaping May Accelerate the Risk
A study published in the journal Cannabis and Cannabinoid Research found that people who used electronic vape cartridges developed CHS symptoms significantly faster than those who smoked marijuana or consumed edibles. The California research team surveyed 1,134 people with CHS and examined their consumption methods, frequency, and symptom timelines.
Researchers pointed to several possible factors for this difference, including higher THC concentrations in vape products, faster absorption into the bloodstream, and stronger peak effects. The study also noted that people who exclusively used vape cartridges tended to consume cannabis more frequently, which may compound the biological risk.
The survey-based study shows an association but does not prove that vaping directly causes earlier onset of the condition. The researchers flagged key limitations: the data relied on self-reporting, participants were recruited from CHS-focused online communities, and detailed information on THC potency was not collected.
For people who follow health and wellness trends, the potency question is relevant beyond CHS – higher-THC products have been independently linked to adverse neurological and psychological outcomes. Learn more about cannabis and the brain.
The Undercounting Problem
The near-400% jump in reported CHS cases did not happen because hundreds of thousands of new people suddenly got sick in the fall of 2025. The dramatic spike reflects improved clinical recognition and coding enabled by the new diagnostic code. Before October 2025, CHS was routinely misdiagnosed as cyclic vomiting syndrome, gastroparesis, or other gastrointestinal conditions – especially in patients who didn’t disclose their cannabis use, or whose providers didn’t think to ask.
Analysis of the post-implementation period from October 2025 to May 2026 shows sustained elevated CHS diagnoses and some ongoing growth, suggesting that while much of the initial surge was a coding artifact, CHS may represent a genuine and growing clinical problem, particularly in younger populations.
The new diagnostic infrastructure has made that burden visible. The nearly 200,000 ED visits logged between January 2023 and May 2026 represent only what the system was equipped to document – a floor, not a ceiling.
Read More: What New Research Actually Says About Cannabis and the Aging Brain
What to Do Now
The CDC’s latest data show that the diagnostic gap, not a sudden outbreak, drove the October 2025 spike. The cases were there before the code existed – they simply weren’t being counted.
For frequent cannabis users – particularly those who vape daily, use multiple times per day, or have noticed recurrent morning nausea – early CHS symptoms are worth discussing with a physician. Researchers found that CHS is strongly associated with persistent and heavy use of inhaled cannabis products, especially THC-containing vape cartridges, and that vape cartridge use was associated with earlier symptom onset than other consumption methods. Morning nausea that responds unusually well to hot showers warrants a clinical conversation, not a web search.
For clinicians, the CDC’s findings point to a clear need: stronger education about risks associated with frequent cannabis use, expanded surveillance, and improved diagnostic practices in emergency settings. CHS has been called rare for two decades largely because no reliable mechanism existed to count it.
Disclaimer: This information is not intended to be a substitute for professional medical advice, diagnosis, or treatment and is for information only. Always seek the advice of your physician or another qualified health provider with any questions about your medical condition and/or current medication. Do not disregard professional medical advice or delay seeking advice or treatment because of something you have read here.
AI Disclaimer: This article was created with the assistance of AI tools and reviewed by a human editor.
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