New CDC report provides new depth in understanding cannabis hyperemesis syndrome

A sharp increase in emergency department visits involving cannabis hyperemesis syndrome may reflect better identification of the condition rather than a sudden increase in the number of people experiencing it, according to a new report from the Centers for Disease Control and Prevention.

The change followed the introduction of the first diagnosis code created specifically for cannabis hyperemesis syndrome, commonly known as CHS.

The new International Classification of Diseases, Tenth Revision, Clinical Modification code, R11.16, took effect on October 1, 2025.

Prior to that, medical providers generally documented suspected cases using a combination of broader codes for vomiting and cannabis-related diagnoses.

According to the CDC report and accompanying data, CHS was involved in 3.35 of every 10,000 emergency department visits in September 2025.

Following the revision and the inclusion of the new coding, that figure increased to 11.26 per 10,000 visits in October.

From October 2025 through May 2026, emergency departments recorded a monthly average of 11.97 CHS-involved visits per 10,000 visits.

A rate 3.7 times the average recorded from January 2023 through September 2025.

The timing and speed of the increase are important. Before the coding change, the monthly rate remained relatively stable for nearly three years, ranging from 2.69 to 3.44 CHS-involved visits per 10,000 emergency department visits.

What the data says

“Scromiting” became a buzzword during the same time period. A 370% increase in CHS? The report details that the timing doesn’t mean there was a 3X increase in CHS occurrences; it simply shows that it was being properly attributed and reported for the first time.

The CDC analyzed information from its National Syndromic Surveillance Program, which receives electronic health data from approximately 7,500 facilities representing 83 percent of U.S. emergency departments.

The study was limited to 3,636 emergency departments that consistently reported data between January 2023 and May 2026.

Researchers identified 199,565 CHS-involved emergency department visits among more than 407 million emergency department visits during the study period.

What is cannabis hyperemesis syndrome?

Cannabis hyperemesis syndrome is a gastrointestinal condition often associated with prolonged, frequent cannabis use.

It can cause recurring episodes of severe nausea, vomiting, and abdominal pain.

CHS can also be difficult to identify because its symptoms resemble cyclical vomiting syndrome and other gastrointestinal conditions. Diagnosis generally depends on clinicians asking about cannabis use and patients accurately reporting how frequently they consume cannabis, how long they have used it, and what types of products they use.

Anecdotally, patients who have used cannabis for long periods have reported CHS at low frequencies for decades. But with added access, increased legal options, and proper tracking, CHS has seen a rise in reported instances.

   

Historically, CHS has been identified most often as affecting those with frequent cannabis consumption patterns, typically daily or multiple times per day for more than one year. However, the CDC noted that emerging evidence suggests symptoms may begin sooner in some people.

Younger patients recorded the highest rate

People between the ages of 15 and 24 had the highest rate of CHS-involved emergency department visits after the new code took effect, at 38.70 visits per 10,000. Those between the ages of 25 and 34 followed at 28.28 visits per 10,000.

Females had a slightly higher recorded rate than males, with 12.65 visits per 10,000 compared with 11.13.

The post-implementation rate was highest among Black patients, at 17.60 visits per 10,000. American Indian and Alaska Native patients followed at 15.14, while Hispanic patients recorded a rate of 12.08.

The demographic figures describe the proportion of emergency department visits associated with CHS within each group. They do not establish why those differences occurred or demonstrate that race or ethnicity is itself a biological risk factor.

Researchers said the higher rate among younger patients could be associated with several changing patterns of cannabis use, including earlier initiation, more frequent consumption, higher-potency products, and consumption methods.

Additionally, intoxicating hemp products

While the CDC cautioned that THC concentration has not been directly linked to CHS.

However, higher-potency products have a more frequent occurrence of reported negative side effects, especially in the case of edibles and hemp derived products.

Recorded visits do not represent every case

The CDC cautioned that the data include only people whose symptoms were serious enough to result in an emergency department visit. The findings do not account for people treated in other medical settings, those who did not seek treatment, or cases that clinicians failed to recognize.

Identification also depends partly on patients disclosing cannabis use. Incomplete reporting or documentation could result in additional cases being missed.

The data should not be interpreted as a complete measurement of how many Americans experience CHS. Likewise, comparisons between the periods before and after October 2025 must account for the significant change in how the condition was identified and coded.

The report also covers only eight months following the introduction of the new code. The CDC said the post-implementation findings should be interpreted cautiously because they could reflect increasing adoption of the code and improved clinical recognition rather than an increase in the condition’s actual incidence.

The new diagnosis code gives health officials a more precise way to monitor CHS, but the CDC said additional education remains necessary.

With research opportunities increasing and the ability for more primary physicians to discuss medical cannabis with their patients a better understanding of CHS lies ahead.

The CDC recommended that emergency clinicians consider CHS when treating patients with recurring nausea, vomiting, and abdominal pain and routinely ask about cannabis consumption, including frequency, duration, product type, and method of use.