NEW YORK (WOWO) — A condition tied to frequent marijuana use is being identified far more often in U.S. emergency rooms, with the biggest proportions of cases involving young people, women and some racial and ethnic groups, according to a new report from the Centers for Disease Control and Prevention.

The CDC says the increase in emergency department visits involving cannabis hyperemesis syndrome, or CHS, became especially pronounced after a new diagnosis code for the condition took effect in October 2025.

CHS causes repeated episodes of severe nausea and vomiting along with abdominal pain and is associated with prolonged, frequent cannabis use.

CDC researchers analyzed emergency department data from January 2023 through May 2026. Nearly 200,000 emergency department visits involving CHS were identified during that period.

The key finding is the dramatic change after the new diagnostic code was introduced.

Before October 2025, the proportion of emergency department visits involving CHS remained relatively stable. In September 2025, there were 3.35 CHS-related visits for every 10,000 emergency department visits.

That number climbed to 11.26 per 10,000 in October, the first month the new CHS-specific code was available.

From October 2025 through May 2026, the average monthly rate was 11.97 CHS-related visits per 10,000 emergency department visits — about 3.7 times the average rate recorded from January 2023 through September 2025.

CDC researchers caution that the numbers do not necessarily mean the actual incidence of the syndrome suddenly tripled or quadrupled.

Instead, the agency says the abrupt and sustained increase likely reflects, at least in part, better recognition and more consistent coding of a condition that previously was often missed or classified as something else.

Before the new code was introduced, doctors and hospitals generally had to identify CHS by combining codes for vomiting or cyclical vomiting with separate codes indicating cannabis use.

The new ICD-10-CM code, R11.16, gives clinicians a specific way to document cannabis hyperemesis syndrome.

The CDC says that change could provide a more accurate picture of how much CHS is affecting emergency departments nationwide.

The data came from the CDC’s National Syndromic Surveillance Program, which receives near-real-time electronic health information from roughly 7,500 health care facilities across all 50 states, the District of Columbia and Guam. For the analysis, researchers used data from 3,636 emergency departments that consistently reported information from January 2023 through May 2026.

The syndrome was identified in 199,565 emergency department visits among more than 407 million all-cause emergency department visits during the study period.

Young people stood out in the findings.

From October 2025 through May 2026, people ages 15 to 24 had the highest average proportion of CHS-related emergency department visits, at 38.70 per 10,000 visits. Black patients had a rate of 17.60 per 10,000, while females had a rate of 12.65 per 10,000.

The higher rates among younger patients were unexpected because CHS has traditionally been associated with heavy, long-term cannabis use.

CDC study author Alana Vivolo-Kantor said the increase among younger patients was “actually one of the surprising findings for us.”

She questioned how long those patients had been using cannabis and how early they may have started.

The CDC report notes that newer research suggests CHS symptoms can develop sooner than previously believed, including within the first year of cannabis use in some cases.

Researchers say several factors could be contributing to the higher rates among younger patients, including earlier initiation of cannabis use, more frequent use, changing perceptions about marijuana’s risks and increased exposure to high-potency THC products.

The CDC also points to changing methods of consumption, including vaping and dabbing.

Dabbing involves inhaling highly concentrated THC oils, according to the agency.

The report does not establish that high-potency THC directly causes CHS. However, CDC researchers note that higher-potency cannabis products have been associated with more frequent cannabis use, and frequent use is the primary known risk factor for the syndrome.

The types of cannabis products being used by younger Americans are also changing. Researchers say more study is needed to understand the effects of high-potency THC and hemp-derived products, including vapes, drinks and gummies.

CHS is believed to have been substantially underrecognized in the past.

The CDC says patients with the syndrome may be diagnosed with other gastrointestinal conditions, including cyclical vomiting syndrome. Doctors also may not routinely ask about or document cannabis use, making the connection more difficult to identify.

The condition can be severe enough to send patients repeatedly to emergency departments. The CDC says outcomes can range from symptoms resolving after cannabis use stops to, in rare cases, death.

The agency’s findings come amid broader changes in cannabis use patterns in the United States. The CDC says past-month and daily or near-daily cannabis use has increased, particularly among young adults and females, while THC concentrations in cannabis products have also increased over time.

The researchers emphasize that the new numbers should be interpreted carefully because the study captures people sick enough to seek emergency medical care and depends in part on patients reporting their cannabis use.

The CDC also says the data may not represent every emergency department equally because the analysis was restricted to facilities with consistent reporting.

Even with those limitations, federal researchers say the new diagnosis code is an important step toward understanding the scope of cannabis hyperemesis syndrome.

The agency recommends that emergency room clinicians consider CHS when evaluating patients with nausea, vomiting and abdominal pain, and routinely ask about cannabis use — including how often it is used, how long it has been used, what type of product is being consumed and how it is being taken.

The CDC says additional education for doctors and the public is particularly important for younger people, given the high proportion of CHS-related emergency visits among patients ages 15 to 24.

The agency also calls for continued surveillance to determine whether the higher levels seen after October 2025 represent a true increase in the condition, better diagnosis, or a combination of both.

For now, the CDC says the most immediate lesson from the data is that cannabis hyperemesis syndrome appears to have been underestimated and that health care providers need to be better equipped to recognize it.