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On CHS and the overdiagnosis problem
Cannabinoid hyperemesis syndrome is real. I'm not going to wave it away. Chronic heavy cannabis use can produce a genuine pattern of cyclic nausea, vomiting, and abdominal pain that resolves with cannabis cessation and temporarily improves with hot showers. People have been hospitalized for it, a small number have died from dehydration complications, and if the pattern fits your experience, taking a real break from cannabis is the evidence-based move. I don't want anyone reading this page to dismiss CHS because they heard a stoner on the internet say it was fake.
That said, the reason CHS earns its own section here is that it's become a shortcut diagnosis in emergency departments, and that shortcut is harming people. A Harvard Medical School cannabinoid specialist recently wrote about exactly this pattern in STAT News, describing how ER physicians, under time pressure and often carrying stigma about cannabis use, will anchor on a patient's admission of cannabis use and stop working the differential diagnosis. The clinical term for this is anchoring bias, and in the published case the specialist walked through, a patient was repeatedly sent home with a CHS diagnosis when what they actually had was superior mesenteric artery syndrome, a rare compression disorder that's potentially life-threatening and that requires actual imaging to catch.
The differential for cyclic vomiting and abdominal pain is enormous. Gallstones, pancreatitis, bowel obstruction, cyclic vomiting syndrome, gastroparesis, appendicitis, SMA syndrome, and more. Any of those can coexist with cannabis use. A doctor writing "CHS" on your chart without ordering the imaging and labs that rule out the serious alternatives is a doctor practicing bad medicine, full stop. If you're a cannabis user presenting to an ER with vomiting, my harm reduction advice is the same as it would be for any interaction with the medical system where you think you're being pattern-matched instead of evaluated: ask what else they've ruled out, ask what imaging they've done, ask what the next step is if the symptoms come back after you stop smoking. If they can't answer those questions, you're not getting the workup you need.
Cannabis use doesn't exempt you from appendicitis. Don't let anyone treat it like it does.
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