Cannabinoid hyperemesis syndrome (CHS) is a condition that affects some people who use cannabis frequently over a long period of time. It causes recurring bouts of nausea, vomiting, and abdominal discomfort. Though once considered rare, CHS is increasingly recognized in clinical settings as more individuals report symptoms consistent with the syndrome.
Early identification and understanding of its patterns are important, especially for those experiencing unexplained digestive issues alongside regular cannabis use.
- Cannabinoid hyperemesis syndrome (CHS) is a condition in long-term, heavy cannabis consumers that causes recurrent bouts of severe nausea and vomiting, oftentimes with temporary relief with hot baths.
- The only cure for CHS is to stop using cannabis; symptoms usually resolve after cannabis cessation, whereas continuing to use marijuana will keep triggering vomiting episodes.
- CHS was once thought to be rare, but a survey found that about 33% of very frequent cannabis users have had CHS symptoms. As daily cannabis use rises, more cases of CHS are being recognized by doctors.
What is cannabinoid hyperemesis syndrome (CHS)?
CHS is a syndrome in which long-term, frequent cannabis use leads to recurring episodes of nausea and vomiting. A telltale sign, in most—but not all—patients, is the compulsive use of hot showers or baths taken for relief during episodes. [1]
CHS was first reported in 2004 (Allen et al.), when doctors linked cyclic vomiting in several patients to long-term cannabis use. [2] It is now well-documented as a medical condition caused by cannabis use. [2]
Why does CHS happen?
The cause of CHS is not fully understood. [1] The leading theory is that long-term THC exposure overstimulates cannabinoid receptors and paradoxically upsets the body’s nausea control. [1] Another hypothesis involves the body’s heat-sensing pathway (the TRPV1 receptors), since hot baths and capsaicin (which activates TRPV1) often relieve symptoms. [5]
Thus, heavy, prolonged cannabis use is the trigger for CHS; beyond that, the exact mechanism is still under study.
How common is CHS?
The exact prevalence of CHS is unknown, but one hospital study found roughly one-third of people who use cannabis daily had CHS symptoms. [3] This suggests CHS is not extremely rare among people who use cannabis frequently. As more people use cannabis daily, more cases of CHS are being recognized by doctors. [4]
Recognizing the signs and phases of CHS
CHS typically has three phases: [1][2][6]
- Prodromal phase: Morning nausea, occasional vomiting, and abdominal discomfort. The person usually continues regular cannabis use during this time.
- Hyperemetic phase: Persistent, intense nausea and frequent vomiting. Abdominal pain may occur. The person oftentimes takes multiple hot showers each day for temporary relief. This phase can cause severe dehydration and electrolyte imbalances, and in extreme cases, even acute kidney failure from fluid loss.
- Recovery phase: After stopping cannabis, the nausea and vomiting resolve, and normal appetite returns over days to weeks. If cannabis use is resumed, CHS will almost always recur.
CHS complications and emergency response
Severe CHS episodes require emergency treatment for dehydration. In the ER, patients are given IV fluids, electrolytes, and often haloperidol to control vomiting (since standard antiemetics often don’t work well). [5]
Topical capsaicin cream can be applied for additional relief. [5] Importantly, patients are advised to stop cannabis use immediately to break the cycle.
CHS diagnosis: What to discuss with your doctor
There’s no single test for CHS. Doctors diagnose it based on your symptoms, medical history, and by ruling out other causes. That’s why it’s crucial to be honest and thorough during the consultation, even if it is uncomfortable. Here’s what to share with your doctor: [1]
- Cannabis use: Be transparent about how often you use cannabis, what forms (smoking, edibles, concentrates), and for how long. Even if you use it medicinally or infrequently, this matters.
- Vomiting pattern: Describe when the nausea or vomiting started, how often it occurs, and whether it follows a cycle (e.g., returning every few weeks).
- Hot shower relief: Mention if taking hot showers or baths provides temporary relief—this is a hallmark sign of CHS.
- Other medications or conditions: Please inform your doctor about any prescription medications, supplements, or existing health conditions, as these may impact the diagnosis.
Doctors typically order lab tests or imaging to exclude other potential causes, such as gastrointestinal disorders or neurological problems. If those tests are normal and your history fits, CHS is likely the diagnosis.
Treatment and recovery: What works (and what doesn't)
During an acute CHS episode, treatment focuses on hydration and symptom control. Rehydration with oral fluids or intravenous fluids is important. For severe nausea, typical antiemetic drugs may have limited effect, so doctors often use, as mentioned, haloperidol or similar medications to stop the vomiting. [5] Applying capsaicin cream to the abdomen (to mimic the hot shower effect) can also help. [5]
Most importantly, the patient must try to stop using cannabis – abstinence is the only definitive cure for CHS. [1]
Myth-busting: Don’t fall for common misconceptions:
- CHS is not due to pesticides or additives. Evidence shows THC itself is the cause of CHS.
- Changing cannabis form won’t help. Smoking vs. edibles vs. vaping – if it contains THC, it can trigger CHS.
- More cannabis won’t cure it. Using more marijuana to treat CHS symptoms will only prolong or worsen the episode.
How long does it take to recover from CHS?
In most cases, once someone with CHS stops using cannabis, improvement usually happens quickly. Many patients feel better within 24–48 hours of their last use, and the vomiting episodes typically end within about a week of abstinence. [1] Most recover within 1–2 weeks, though some need several weeks. However, if they use cannabis again, the symptoms tend to come back almost every time. [2]
Prevention & harm reduction
- Best protection — skip chronic use. Long-term, near-daily cannabis exposure is the only confirmed trigger for CHS, so the surest safeguard is to use occasionally or abstain altogether.
- Spot the prodrome. Morning queasiness or mild vomiting that eases under a hot shower is an early warning sign. If that happens, try to pause all cannabis for at least a week, hydrate, and monitor. Catching it here often averts the full hyper-emetic phase. [7]
- Lower-risk use, if you choose to continue: (a) Limit to 1–2 days per week and prefer lower-THC flower over high-potency vapes, dabs, or edibles; (b) Take regular tolerance breaks (more than 48 hours); (c) Avoid using on an empty stomach and layer caffeine or alcohol cautiously (they can mask prodromal cues). [8]
After CHS recovery, even tiny amounts can reignite symptoms. Total abstinence is the only proven way to stay episode-free.
When to seek care?
Inability to keep fluids down for 24 hours, severe abdominal pain, or signs of dehydration warrant an emergency department visit.
CHS and cannabis use disorder treatment
Quitting cannabis can be challenging for frequent consumers. If you have CHS and struggle to quit, seek help for cannabis use disorder. This might include counseling, support groups, or rehab programs.
Visit our cannabis treatment page for more details. You can also call the Substance Abuse and Mental Health Services Administration (SAMHSA) National Helpline at 1800-662-4357. It’s a free, confidential service available 24/7, 365 days a year.
Getting support is important – addressing the underlying dependence will ensure CHS is cured and doesn’t return. [2]
-guide-detail.jpg?v=1756808779)