What is Cannabinoid Hyperemesis Syndrome?

A paradoxical disorder in chronic high-dose cannabis users: cyclic vomiting, abdominal pain, and characteristic relief with hot showers. Rome IV diagnosis; the only causal therapy is complete cannabis abstinence.

How long is recovery?

Acute vomiting resolves within 48 h – 1 week after abstinence; full endocannabinoid recovery 2–8 weeks.

Is dose reduction enough?

No. Practically every documented case relapses on any resumption. Only full abstinence is curative.

Pure CBD does not appear to trigger CHS but is not a substitute or therapy for manifest CHS. Safer to pause all cannabinoids until recovery.

Where to seek help in Switzerland?

University hospital ER (USZ, USB, Inselspital, CHUV, HUG), your GP, gastroenterology outpatient clinics, Sucht Schweiz 0800 104 104 for abstinence support.

Cannabinoid Hyperemesis Syndrome (CHS): Symptoms, Diagnosis, Treatment Switzerland 2026 | CannabisClub.ch

Evidence-based guide to CHS: Rome IV criteria, three phases, emergency therapy (capsaicin, haloperidol), abstinence and help in Switzerland.

Cyclic vomiting, intractable nausea, repeated hot showers — chronic, high-dose cannabis use can lead to Cannabinoid Hyperemesis Syndrome (CHS). A paradoxical, often-missed disorder with clear diagnostic criteria (Rome IV) and only one effective therapy: complete abstinence.

TL;DR — CHS

CHS = paradoxical vomiting after years of near-daily high-THC use.
Prevalence: Habboushe 2018 estimates ~2.7 M US adults symptomatic.
Three phases: prodromal → hyperemetic → recovery.
Cardinal sign: relief with hot shower/bath (TRPV1).
Diagnosis: Rome IV; exclude ulcer, gastroparesis, CVS.
Only causal therapy: permanent cannabis abstinence.

What is CHS?

First described systematically by Allen et al. (2004). Occurs in a minority of chronic users through paradoxicaldysregulation of the endocannabinoid system: cannabis is antiemetic at normal doses (see medical cannabis), but becomes emetogenic under chronic overexposure.

Three phases

1. Prodromal

Morning nausea, abdominal pain, appetite loss — months to years. Users often increase intake believing cannabis is antiemetic. That drives progression.

2. Hyperemetic

Explosive intractable vomiting (up to 5–10×/h), abdominal pain, dehydration. Prolonged hot showers bring reliable relief — pathognomonic.

3. Recovery

After full abstinence symptoms remit within 48 h – 2 weeks. Any relapse to cannabis typically brings symptoms back.

Why does a hot shower help?

Heat activates TRPV1 in skin (~43 °C). TRPV1 and CB1 share signaling in the brainstem vomiting center; TRPV1 activation counters the chronically dysregulated CB1 signaling. Topical capsaicin 0.075 % on abdomen/back exploits the same mechanism — now standard adjunct therapy.

Diagnosis (Rome IV)

Stereotypical vomiting episodes resembling CVS.
Onset after chronic frequent cannabis use.
Relief by prolonged hot bathing/showering.
Resolution after > 6 months of abstinence.
Exclude ulcer, cholecystitis, gastroparesis, porphyria, pancreatitis, adrenal insufficiency.

Emergency management

IV rehydration.
Topical capsaicin 0.075 %.
Haloperidol 2.5–5 mg IM/IV — small RCTs favor over ondansetron.
Benzodiazepines as adjunct.
Ondansetron often only weakly effective in this indication.
Critical patient education: cannabis is cause, not therapy.

Recurrent vomiting with daily use?Talk to your GP or an ER and actively mention CHS — it's frequently missed. Full abstinence is the only durable path.
See our T-Break guide & responsible use →

Long-term therapy

Only causal therapy: permanent full abstinence. See our cannabis withdrawal guide and the T-Break protocol. Relapse > 6 months later leads to recurrence in nearly 100 % of cases.

CBD and CHS

Pure CBD does not appear to trigger CHS but is not a substitute once CHS is manifest. Dosage details in the CBD dosage guide.

Where to seek help — Switzerland

University hospital ER (USB, Inselspital, USZ, CHUV, HUG).
Your GP for first evaluation.
Gastroenterology outpatient clinics.
Sucht Schweiz 0800 104 104 for abstinence support.
SafeZone.ch anonymous online counselling.

FAQ

How common is CHS? Underdiagnosed; Habboushe 2018 estimates ~2.7 M US adults with CHS-consistent symptoms.

How long until symptoms resolve? Acute vomiting 48 h – 1 week; full recovery 2–8 weeks.

Can lower dose control CHS? No — full abstinence only.

Confused with CVS? Frequently. Cyclic Vomiting Syndrome is the key differential; the cannabis history distinguishes.

Is CBD ok during CHS? Evidence lacking; safer to pause all cannabinoids until recovery.

Changelog

July 2026: first publication.

Frequently asked questions

What is Cannabinoid Hyperemesis Syndrome?: A paradoxical disorder in chronic high-dose cannabis users: cyclic vomiting, abdominal pain, and characteristic relief with hot showers. Rome IV diagnosis; the only causal therapy is complete cannabis abstinence.
Why does a hot shower help?: Above ~43 °C heat activates skin TRPV1 receptors, which share signaling pathways with CB1 in the brainstem vomiting center. TRPV1 activation counters chronically dysregulated CB1 signaling. Topical capsaicin 0.075 % uses the same mechanism.
How long is recovery?: Acute vomiting resolves within 48 h – 1 week after abstinence; full endocannabinoid recovery 2–8 weeks.
Is dose reduction enough?: No. Practically every documented case relapses on any resumption. Only full abstinence is curative.
Can CBD help?: Pure CBD does not appear to trigger CHS but is not a substitute or therapy for manifest CHS. Safer to pause all cannabinoids until recovery.
Where to seek help in Switzerland?: University hospital ER (USZ, USB, Inselspital, CHUV, HUG), your GP, gastroenterology outpatient clinics, Sucht Schweiz 0800 104 104 for abstinence support.