If you’ve never heard of cannabinoid hyperemesis syndrome, you’re not alone — but Virginia hospitals are seeing it more and more.

A new analysis by the Virginia Hospital and Healthcare Association found that emergency room visits linked to a condition that causes uncontrollable nausea, vomiting and abdominal pain in long-term marijuana users increased nearly 29 percent in Virginia between 2020 and 2024. In total, nearly 25,000 Virginians visited an emergency room for the condition — known as CHS — over that five-year period, climbing from about 4,000 visits in 2020 to more than 5,100 in 2024.

CHS is not widely understood by the general public, and many sufferers don’t immediately connect their symptoms to marijuana use. The condition tends to affect people who have used cannabis heavily for an extended period of time and causes recurring bouts of severe vomiting that can be serious enough to require emergency care.

The Virginia numbers are part of a broader national trend. A study published in the Journal of the American Medical Association found CHS cases rising in U.S. emergency rooms from 2016 through 2022, with the heaviest concentration among adults aged 18 to 35. Research out of Northern California documented a 134 percent increase in CHS-related ER visits over an 11-year period. A Colorado study found a 46 percent increase in related hospitalizations in just four years.

Zooming out further, Virginia emergency rooms saw nearly 173,000 visits related to cannabis abuse, dependence or poisoning between 2020 and 2024 — more than 31,000 per year, with a peak of nearly 38,000 in 2022.

The VHHA analysis was based on all-payer emergency department and hospital discharge data for the five-year period.

Information from a release. Edited by Dan McDermott.