What is CHS? Marijuana advocates warn of a little-known condition affecting heavy users

As more and more U.S. states expand marijuana legalization, and with weed usage on the rise, doctors and advocates are warning about a little-known condition affecting heavy users of the drug.

Cannabinoid hyperemesis syndrome, or CHS, causes severe abdominal pain, nausea and “cyclic vomiting” among regular marijuana users — and can lead to extreme dehydration and, in rare cases, death.

“It’s very underdiagnosed,” said Dr. Joseph Habboushe, an assistant professor of emergency medicine at New York University Langone/Bellevue Medical Center, who co-authored a 2018 study on CHS. “Doctors aren’t thinking...