Cannabis
Cannabinoid Hyperemesis Syndrome (CHS): Symptoms, Causes, and Treatment
Cannabinoid hyperemesis syndrome, or CHS, puts some long-term, frequent cannabis users through repeated episodes of severe nausea, vomiting, and abdominal pain. Its strange calling card is the shower. Many people with CHS discover that hot water is the only thing that eases the symptoms, and they start taking several scalding showers a day. That is a useful clue. It is not, by itself, a diagnosis.
What makes CHS so disorienting is that cannabis may once have seemed to help with nausea. So the person uses more to settle their stomach, and the continued use keeps the cycle going. We see this at South Jersey Recovery Program in people who have been through scans, endoscopies, and gallbladder workups before anyone asked the one question that mattered.
What CHS is
The National Library of Medicine’s clinical reference, StatPearls, defines CHS as cyclical nausea, vomiting, and abdominal pain after cannabis use, typically following several years of preceding use, with episodes recurring every few weeks to months. A 2017 systematic review in the Journal of Medical Toxicology pulled together 183 published reports and found a consistent profile:
- A history of regular cannabis use in every case, and at least weekly use in 97%
- Cyclic nausea and vomiting in every case
- Abdominal pain in 85%
- Compulsive hot baths or showers that relieve symptoms in 92%
- Resolution of symptoms after stopping cannabis in 97%
That last figure is the whole story in one number. CHS stops when the cannabis stops.
The three phases
Prodromal. Early on: morning nausea, abdominal discomfort, and sometimes a growing dread of vomiting before vomiting itself becomes the dominant problem. Symptoms this ordinary have a hundred causes, which is exactly why CHS gets missed at this stage.
Hyperemetic. The crisis. Intense nausea, repeated vomiting, and abdominal pain, often lasting a day or more. This is when the hot showers start. Standard anti-nausea medications often fail.
Recovery. Symptoms improve after cannabis is stopped, and the diagnosis is confirmed in hindsight by two things: sustained recovery while abstinent, and the return of symptoms if cannabis resumes.
When CHS is an emergency
Repeated vomiting can cause severe dehydration, dangerous electrolyte changes, and kidney injury. StatPearls also lists nutritional deficiencies, aspiration into the lungs, and injury to the esophagus among the complications. Go to an emergency department for:
- Inability to keep fluids down for more than a few hours
- Very little urination, fainting, or confusion
- Vomiting blood
- Severe or worsening abdominal pain, chest pain, or trouble breathing
Poison Control at 1-800-222-1222 can provide immediate guidance, but it cannot replace emergency care when those signs are present.
Why it gets missed
CHS hides for two reasons. First, patients rarely volunteer their cannabis use, and many sincerely disbelieve the connection. Cannabis is their anti-nausea remedy, so stopping it sounds like the opposite of a cure. Second, the workup for cyclic vomiting is genuinely broad, and it is not wrong for a physician to rule out the other causes.
For recurrent unexplained vomiting there is one screening question that earns its keep: does a hot shower help? An emphatic yes, plus regular cannabis use, moves CHS to the top of the list. Hot-water relief also occurs in cyclic vomiting syndrome without cannabis, which is why the cannabis history matters as much as the shower.
The condition is also becoming more common as products get stronger. A 2019 study of emergency visits at a Denver hospital found that visits attributable to inhaled cannabis were more likely to be for CHS than visits attributable to edibles, at 18% versus 8%.
Treatment: the episode and the cure
In the emergency department, treatment for an acute episode can mean IV fluids, electrolyte correction, and medication for nausea, pain, or agitation. Some emergency departments use haloperidol or topical capsaicin cream, which StatPearls reports has produced significant relief of pain and vomiting in published cases. These belong in a clinician’s hands, not a home medicine cabinet.
All of that treats the episode. StatPearls is direct about the rest: the only definitive treatment of cannabinoid hyperemesis syndrome is the removal of cannabis exposure. Cutting back is usually not enough. Improvement is not always immediate, and other conditions can also cause cyclic vomiting, which is why the right move is to stay connected to a clinician rather than self-diagnose and disappear.
The hard part is the quitting
“Just stop” is easy to write and hard to live, especially for someone who has used daily for years. Many people with CHS meet criteria for cannabis use disorder, and stopping brings cannabis withdrawal: irritability, insomnia, restlessness, and cravings that peak in the first week. That is the window where most quit attempts fail, and it is the window structured treatment is built for.
At South Jersey Recovery Program in Berlin, NJ, cannabis use disorder is treated on an outpatient basis, through partial care, an intensive outpatient program, or standard outpatient therapy, while clients keep living at home. We coordinate with the client’s medical providers, because a person with CHS needs both the vomiting managed and the cannabis use treated. Our marijuana addiction treatment page explains how we match the level of care to the person. New Jersey’s free 24-hour addiction helpline, ReachNJ, is at 1-844-732-2465.
At a glance
- CHS causes cycles of severe nausea, vomiting, and abdominal pain in long-term, near-daily cannabis users.
- Relief from hot showers is the classic clue, present in about 92% of published cases, though it also occurs in cyclic vomiting without cannabis.
- Complications such as dehydration, electrolyte imbalance, and kidney injury can be dangerous. Inability to hold fluids is an emergency department visit.
- Symptoms resolve after stopping cannabis in about 97% of cases. That is the treatment.
- Quitting is hard precisely because many people with CHS have cannabis use disorder. Outpatient treatment exists for exactly that.
Sources
- Chu F, Cascella M. Cannabinoid Hyperemesis Syndrome. StatPearls, National Library of Medicine. ncbi.nlm.nih.gov/books/NBK549915
- Sorensen CJ, et al. Cannabinoid Hyperemesis Syndrome: Diagnosis, Pathophysiology, and Treatment, a Systematic Review. Journal of Medical Toxicology. 2017;13(1):71-87. pubmed.ncbi.nlm.nih.gov/28000146
- Rubio-Tapia A, McCallum R, Camilleri M. AGA Clinical Practice Update on Diagnosis and Management of Cannabinoid Hyperemesis Syndrome. Gastroenterology. 2024;166(5):930-934. pubmed.ncbi.nlm.nih.gov/38456869
- Monte AA, et al. Acute Illness Associated With Cannabis Use, by Route of Exposure. Annals of Internal Medicine. 2019;170(8):531-537. pubmed.ncbi.nlm.nih.gov/30909297
- Connor JP, et al. Clinical management of cannabis withdrawal. Addiction. 2022;117(7):2075-2095. pubmed.ncbi.nlm.nih.gov/34791767
- ReachNJ, New Jersey’s addiction helpline. nj.gov/humanservices/reachnj
