A new CDC report says recorded cannabis hyperemesis emergency department visits jumped 3.7 times after the condition got its own diagnosis code — and CDC itself says most of that jump is better counting, not a sudden wave of illness. That distinction is going to get flattened in a lot of headlines this week, so let us get it right.
The report is MMWR Vol. 75, No. 30, pages 391-396, published August 6, 2026.
What the cannabis hyperemesis numbers actually say
Cannabis hyperemesis syndrome is cyclical severe nausea, vomiting and abdominal pain associated with prolonged frequent cannabis use. Until recently there was no specific code for it — cases had to be identified by combining a vomiting code with a cannabis-related code, which meant many were classified as something else.
On October 1, 2025, it got its own ICD-10-CM code: R11.16. Here is what happened next. Recorded CHS-involved ER visits went from 3.35 per 10,000 all-cause ED visits in September 2025 to 11.26 in October 2025 — the very first month the code existed. Across the first eight months with the new code the average was 11.97 per 10,000, which is 3.7 times the January 2023 to September 2025 average of 3.19.
Total volume: 199,565 CHS-involved ED visits out of 407,326,613 all-cause visits between January 2023 and May 2026. The data come from CDC’s National Syndromic Surveillance Program, covering roughly 83 percent of U.S. emergency departments.
Why “ER visits tripled” is the wrong headline
CDC says so directly in its own discussion section: “The abruptness and sustained magnitude of the increase likely reflects, at least in part, improved clinical recognition and coding of CHS rather than a true and immediate rise in incidence.”
Think about what a step change in a single month means. Nothing about cannabis consumption in America changed between September 30 and October 1, 2025. What changed was the form. When you give clinicians a box to check, they check it — and cases previously filed as cyclical vomiting syndrome start showing up in the count.
But do not swing too far the other way, because CDC’s second point matters just as much: the new, higher number is probably the more accurate one. The agency writes that the findings “highlight a likely underestimated impact of CHS.” In other words, it was being undercounted before. Both things are true at once — the increase is an artifact, and the problem was bigger than we thought.
Two more caveats. These are visits, not people; this is a repeat-visit condition, so one patient can appear many times. And these are only patients sick enough to go to an emergency room, so true prevalence is higher than either figure.
The part a cannabis show should say out loud
The demographic breakdown is the genuinely useful finding, and we are not going to soft-pedal it. The highest average monthly proportions were among people aged 15-24, at 38.70 per 10,000 — roughly three times the overall average. Ages 25-34 came in at 28.28. Black patients averaged 17.60; females 12.65 versus 11.13 for males.
CDC also notes onset can come faster than clinicians assumed: “emerging evidence indicates that symptom onset can occur much sooner than was previously estimated, including within the first year of cannabis use.”
Here is our position. If this industry wants to be treated as legitimate, it has to be able to say that heavy, daily, high-potency use in young people has a real downside — and mean it. Pretending otherwise makes us indistinguishable from the people who spent forty years telling obvious lies in the other direction. Cannabis hyperemesis is real, it is miserable, it is concentrated in young heavy users, and it is treatable. The treatment is stopping.
Budtenders and operators can do something useful with this: if a regular customer mentions cycles of vomiting and hot showers, that is not a stomach bug. Tell them to see a doctor and mention their cannabis use, because the diagnosis is easy to miss and the workup gets expensive when it goes the wrong direction.
Related coverage: the Senate hemp ban delay and workplace drug testing in 2026.
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We break this down on Cannabis Legalization News with Thomas Howard and Miggy 420.
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Original sources
- CDC MMWR 75(30);391-396 (Aug. 6, 2026) · PDF · DOI 10.15585/mmwr.mm7530a2
- ICD-10-CM code packet introducing R11.16
- CDC National Syndromic Surveillance Program
