Cannabinoid hyperemesis syndrome is a condition caused by chronic cannabis use that manifests as serious nausea, abdominal pain, and frequent vomiting. If symptoms go untreated, patients can develop other related conditions, most notably severe dehydration. Cannabinoid hyperemesis syndrome (CHS) appears to be a relatively rare condition, and only affects people who consume heavy doses of marijuana, frequently, for a long period of time.
While much remains unknown about the syndrome, researchers currently believe that the only truly effective treatment is to stop consuming marijuana.
Overview: marijuana use and cannabinoid hyperemesis syndrome
As with many questions related to marijuana consumption, there is limited research into CHS. In the US and elsewhere, this is due primarily to legal challenges arising from decades of marijuana prohibition laws. Compounding things further, because the condition was first described in 2004, less than two decades ago, CHS research is particularly sparse.
However, current research suggests that CHS occurs as a result of overstimulating parts of the endocannabinoid system — specifically the endocannabinoid receptors located in the gut. This level of overstimulation occurs as a result of chronic cannabis use.
Marijuana produces its effects when THC and other cannabinoids produced by the cannabis plant bind to and interact with endocannabinoid receptors located throughout the body. In general, when cannabinoids bind to those receptors they produce the feeling of being high, as well as feelings related to mood regulation, sleep, appetite, and more. For many people, the interaction between cannabinoids and receptors in the brain also helps relieve feelings of nausea.
At the same time, cannabinoids from marijuana also bind to and interact with endocannabinoid receptors in your gut. This can sometimes produce very different effects from what's going on in your brain. Nausea is a great example of this. Researchers believe that while cannabinoid activity in the brain of a cannabis consumer may reduce nausea, cannabinoid activity in the consumer's gut can actually create nausea.
If people consume high doses of marijuana for a long period of time, they may start to experience regular and severe bouts of nausea and vomiting, as well as abdominal pain. Infrequent or short-term cannabis use typically does not trigger CHS. Prolonged or intense stimulation of the endocannabinoid system (with daily cannabis use and/or high potency products) is far more likely to trigger CHS.
There are very few epidemiological studies regarding the prevalence of CHS.
But some current research suggests that more potent, high-THC strains may be contributing to an uptick in cannabis-related conditions among people who consume high levels of marijuana. These conditions include cannabis use disorder and cannabinoid hyperemesis syndrome.
Symptoms of cannabinoid hyperemesis syndrome
Recent discussions of CHS, especially in pop culture, often focus on a symptom called “scromiting.” According to fact-checking website Snopes.com, this portmanteau—a mash-up of scream and vomiting—first showed up in a 2017 article about CHS published in the UK tabloid Metro that said people with CHS often experience an unusual combination of screaming and vomiting at the same time. It is unclear if this symptom is widespread or not, but given that severe nausea and vomiting are the main symptoms of CHS, screaming while vomiting could theoretically be something that certain CHS patients experience. It is also likely that this story may be sensationalizing a very rare symptom rather than describing a common symptom.
According to trusted medical research, the primary symptoms of cannabinoid hyperemesis syndrome include:
- Severe nausea
- Cyclic vomiting and abdominal pain
Vomiting is by far the most dangerous symptom of cannabinoid hyperemesis syndrome. While CHS-related vomiting is often similar to something like morning sickness, vomiting episodes associated with cannabinoid hyperemesis syndrome can also be much more severe, occurring up to 20 times per day. Such severe vomiting often leads to dehydration, electrolyte loss, weight loss, and a general feeling of disorientation, all of which can open the door to other, more severe health complications.
For many patients who experience CHS, these intense bouts of nausea and vomiting are separated by asymptomatic periods, which can last for months before symptoms return.
Medical professionals recognize CHS as unfolding in three main stages:
- Prodromal phase. This is the beginning stage of CHS. Many cannabis users will begin to develop abdominal pain and early morning nausea. Heavy vomiting does not typically occur in this stage but patients may begin to develop a fear of nausea and vomiting. Typically, patients can still eat normally during this phase. The prodromal phase may last for several months or even years before moving to the second stage.
- Hyperemetic phase. The hyperemetic phase is characterized primarily by ongoing nausea and heavy vomiting. Abdominal pain, which is present in most cases, continues. Vomiting may be severe enough to require medical attention, especially if the patient becomes severely dehydrated and experiences extreme electrolyte loss. As a result of all the nausea and vomiting, patients in the hyperemetic phase often decrease their food intake, which may cause weight loss and further dehydration. Stopping cannabis use is the only proven way to stop the hyperemetic phase. Because hot showers or hot bathing offer short-term relief from some of these symptoms, this phase is also sometimes marked by compulsive bathing or showering.
- Recovery phase. Patients generally see their symptoms subside and their appetite return within 24 to 48 hours of ending marijuana consumption. Symptoms generally return if patients begin consuming marijuana again. Certain triggers, such as stress, infections, or menstrual periods, may also lead users from the recovery phase back to the prodromal phase.
Outside of stopping marijuana use altogether, there is no consistent or proven treatment for cannabinoid hyperemesis syndrome.
When it comes to treating the feelings of nausea brought on by CHS, anti-nausea treatments, either over-the-counter or by prescription, typically are not useful.
However, many people manage to find nausea relief by taking hot showers or bathing in hot water or applying a topical capsaicin cream. Hot bathing may become compulsive in CHS patients. Relief by hot showering or bathing is reported in about 60% of people with CHS.
In some case studies, benzodiazepines, including lorazepam and alprazolam, have also been shown to relieve some of the symptoms experienced by CHS patients. Other treatments include extensive rehydration with intravenous fluids and the use of proton pump inhibitors, which reduce stomach acid production.
However, stopping marijuana use is the only proven long-term treatment of this condition.
If a cannabis user has experienced severe vomiting, he or she may need hospitalization for treatment of dehydration or stomach inflammation. Electrolyte depletion can lead to serious complications such as seizures, kidney failure, shock, and brain swelling, each of which requires additional medical treatment. CHS, therefore, can become a contributing factor in death from these other complications.
Heavy, long-term cannabis users who experience periods of severe, frequent vomiting for a day or longer should immediately stop consuming marijuana and contact their healthcare provider or visit an urgent care facility to pursue treatment.
Diagnosing cannabinoid hyperemesis syndrome
Although often misdiagnosed, if symptoms of CHS are present and no other underlying cause is responsible for persistent nausea and vomiting, you may want to seek a diagnosis. To arrive at an accurate diagnosis, physicians may look at how often and how much cannabis you use. Be honest with your doctor about your marijuana use. Daily cannabis use and/or high doses of THC are more likely to cause CHS, but a physical exam is often required to rule out other causes.
Currently, the only surefire method that physicians can use to distinguish CHS from other potential illnesses is by observing how the patient's symptoms respond to heat or topical capsaicin. Other tests may be performed to rule out other causes of vomiting, such as a pregnancy, since CHS symptoms can mimic morning sickness; a blood test for anemia or infection; a drug screen; and a urine analysis. Expensive and non-diagnostic imaging scans for CHS-related symptoms are usually unnecessary, but in some cases, an abdominal CT scan or X-rays may be ordered to determine if there is a serious issue such as a blockage that may require surgery.
Nearly 85% of physicians do not receive education about the endocannabinoid system or the effects marijuana can have on the brain and body. Because doctors have limited awareness of CHS, it may be difficult for a health care provider to diagnose and treat the condition. Cyclic vomiting syndrome (CVS) causes similar symptoms, making it a bit more difficult to reach a conclusive diagnosis.
Criteria for CHS diagnosis
The following criteria can help lead to an accurate CHS diagnosis and management of symptoms, and reduce the need for unnecessary and expensive medical testing. To be diagnosed with CHS, a patient must be a chronic cannabis user who:
- Experiences cyclic vomiting syndrome marked by episodes of severe nausea, vomiting, and stomach pain, with cycles lasting on average three days
- Has lost over 10 pounds
- Feels relatively well between cyclical episodes and eats normally
- Does not respond to conventional antiemetic (anti-nausea) or analgesic (painkiller) treatments, but symptoms are relieved after hot baths or showers or topical capsaicin cream
- Has no apparent organic cause for the symptoms
- No longer experiences CHS symptoms once stopping cannabis use
Marijuana users who experience persistent nausea and vomiting should consider seeking a diagnosis to find out if they have CHS. In the meantime, hot showers or hot bathing may offer short-term relief.
Prevention of cannabinoid hyperemesis syndrome
It isn't entirely known what causes some people to experience the symptoms of CHS while others do not. Some people may be predisposed to CHS — with the typical antiemetic effects of THC outweighed by its pro-emetic effect in the gut — while the accumulation of THC in long-term marijuana users may increase the risk of CHS. Plenty of regular, long-term, and higher-quantity users of cannabis do not report CHS symptoms. However, it may take years for CHS to develop.
Most cases of CHS have been shown to occur in people who consume marijuana roughly 20 days per month, and about 75% of those patients have used cannabis regularly for more than a year. More than 70% of CHS sufferers are men.
The best way to prevent CHS is to use cannabis in moderation. High doses, frequent use, and high-potency THC products are the biggest risk factors for developing CHS.
Frequently asked questions
Is cannabinoid hyperemesis syndrome dangerous?
CHS can become dangerous if the patient does not stop consuming cannabis and if the disorder is left untreated. Specifically, CHS becomes dangerous when the primary symptoms of the condition — abdominal pain, nausea, and vomiting — become so severe that the patient ends up becoming severely dehydrated. When that happens, the patient can experience a type of kidney failure increasingly known as cannabinoid hyperemesis acute renal failure, and this condition can quickly lead to much more severe health complications including, in the most extreme cases, death. This is why it's so important to immediately contact your physician if you experience symptoms of CHS, and to stop consuming cannabis right away.
Is cannabinoid hyperemesis syndrome permanent?
CHS is not permanent. It is a result of long-term cannabis use, and symptoms typically end when patients stop consuming cannabis. But they can also flare back up again if the patient returns to regular cannabis use.
How long does it take to recover from cannabinoid hyperemesis syndrome?
CHS symptoms generally begin to subside fairly quickly during the recovery phase, usually within a day or two of cannabis use cessation. To fully recover from CHS, a patient will need to stop consuming cannabis altogether — this is the only proven permanent treatment for CHS. Assuming they do not begin consuming cannabis again, CHS patients can expect a relatively rapid and permanent recovery.
Can CBD cause cannabinoid hyperemesis syndrome?
The limited research into CHS seems to suggest that CBD, along with THC and many other cannabinoids, may indeed contribute to the disorder in long-term users of cannabis. Basically, any type of cannabinoid use for a prolonged period of time may contribute to the onset of CHS.
According to a 2018 article published in The Journal for Nurse Practitioners, “the cannabinoid CBD, in large doses, increases the symptoms of stomach pain, nausea and vomiting.” Another study, this one published in 2011, said that “the pro-emetic properties of CBD (at higher doses) and CBG may play a role in the severe nausea and vomiting observed in patients with Cannabinoid Hyperemesis Syndrome.”
Can you still smoke with cannabinoid hyperemesis syndrome?
No, not cannabis. In fact, research shows that when people with CHS resume smoking marijuana, they typically start experiencing symptoms again, most notably stomach pain and cyclic nausea and vomiting. Once you have CHS, the only proven way to treat it and keep it from returning is to stop consuming cannabis.
How long does it take to develop CHS?
Cannabinoid hyperemesis syndrome is a result of chronic cannabis use. And according to medical experts, people who develop this condition typically begin experiencing symptoms after one to five years of frequent, regular, heavy marijuana use. If you're a chronic marijuana user and you're experiencing symptoms, it may be time to seek a diagnosis.