Cannabinoid Hyperemesis Syndrome: When Cannabis Turns on Its Heaviest Users

Cannabinoid hyperemesis syndrome, or CHS, causes repeated episodes of severe nausea, vomiting, and abdominal pain in some people who use cannabis frequently over a long period. Many people with CHS report that hot showers or baths temporarily ease the symptoms, but that clue is not enough to diagnose the condition by itself.

CHS can be confusing because cannabis may have once seemed to reduce nausea. A person may use more cannabis in an attempt to settle the stomach, while continued use may prolong the cycle. Other serious causes of vomiting and abdominal pain can look similar, so a clinician must consider the full picture rather than assuming every frequent cannabis user has CHS.

The three phases

1. Prodromal phase

This early phase may involve morning nausea, abdominal discomfort, or fear of vomiting before repeated vomiting becomes the dominant problem. Because those symptoms have many possible causes, CHS is often not recognized at first.

2. Hyperemetic phase

The acute crisis involves intense nausea, repeated vomiting, and abdominal pain. Some people take frequent hot showers or baths because heat provides temporary relief. Episodes and intervals vary, and hot-water behavior is a clue—not proof—of CHS.

3. Recovery phase

Symptoms improve after cannabis is stopped, but the timeline varies. Long-term recovery and the return of symptoms after cannabis is resumed can help distinguish CHS from other vomiting disorders.

Who gets CHS

CHS is most strongly associated with frequent, long-term cannabis use. Not every frequent user develops it, and researchers are still studying why. Product potency may matter, but current evidence does not support predicting exactly who will develop CHS or how quickly it will appear.

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, and stopping it feels like the opposite of the cure. Second, the workup for cyclic vomiting is genuinely broad, and patients often cycle through scans, endoscopies, and gallbladder evaluations for years. A useful screening question for anyone with recurrent unexplained vomiting is simply: does a hot shower help? An emphatic yes, plus regular cannabis use, makes CHS the leading suspect.

Treatment: the acute episode and the actual cure

Emergency treatment may include IV fluids, electrolyte correction, and medication for nausea, pain, or agitation. Some emergency departments use medicines such as haloperidol or droperidol, or topical capsaicin, but these treatments have risks and should be directed by a clinician.

Acute treatment addresses the episode. Sustained cannabis abstinence is the central treatment for preventing CHS from returning. Cutting back may not be enough. Because improvement is not always immediate—and because other conditions can cause cyclic vomiting—follow-up with a clinician matters.

The hard part is the quitting

Telling a long-term, frequent user to simply stop is easy to write and hard to live. Some people experience cannabis withdrawal, including irritability, insomnia, restlessness, and appetite changes. Others may have cannabis use disorder and need more than willpower. Outpatient counseling, cognitive behavioral therapy, contingency management, and—in more severe cases—structured treatment can help. Our guided treatment assessment explains common levels of care, and SAMHSA's free helpline (1-800-662-4357) connects people to treatment resources confidentially, 24/7.