Cannabinoid hyperemesis syndrome (CHS) is a rare, but growing, condition of repeated and severe bouts of vomiting experienced by some marijuana users. The syndrome is difficult to predict or diagnose at this time, although its prevalence may be associated with the increased use and potency of the drug.

Some long-term, daily marijuana users develop CHS late in life, while some young people also suffer from it after a few years of heavy smoking. THC, the psychoactive component of marijuana, is thought to be responsible for CHS symptoms, because it binds to receptors in the body’s endocannabinoid system that regulate sleep and other bodily functions.

Although the exact mechanisms that trigger this illness remain unclear, mounting evidence suggests that prolonged cannabis use can lead to the rewiring of receptors and nerves in the gut and esophageal sphincter, leading to CHS symptoms. Some patients have found relief by rubbing creams with capsaicin—a chili pepper extract—on their arms or belly. Experts believe that the warming sensation created by these balms activates a receptor in the stomach that can calm nausea and vomiting.