What is Cannabinoid Hyperemesis Syndrome (CHS)?

Cannabis products are frequently used to reduce symptoms of certain medical conditions, but in rare cases, prolonged cannabis use may result in certain symptoms like nausea, vomiting, and abdominal pain. A 2004 study found a correlation between cannabis use and a cyclical vomiting illness. This condition is known as cannabinoid hyperemesis syndrome and it is widely believed to be caused by long-time, daily cannabis consumption. 

Since cannabinoid hyperemesis syndrome was discovered fairly recently, there is still a lot that researchers do not know about the condition. One 2018 study estimates that approximately 2.75 million Americans may suffer from CHS each year, but the true prevalence of the illness is largely unknown. When you take into account the millions of people in the United States who consume cannabis without complications, CHS is extremely rare. That said, it’s important for cannabis consumers to be aware of CHS, including its symptoms, causes, and how the condition is treated.

What Are the Symptoms of Cannabinoid Hyperemesis Syndrome?

Cannabinoid hyperemesis syndrome is divided into three different phases, which are described in a 2013 article from Hospital Pharmacy journal. The initial phase—also known as the prodromal phase—is characterized by mild symptoms and can last for months or years. During this time, patients may experience early morning nausea, a fear of vomiting, and abdominal discomfort. 

The second phase is known as the hyperemetic phase, and may include the following symptoms:

  • Persistent nausea
  • Vomiting
  • Abdominal pain 
  • Dehydration 
  • Decreased appetite and weight loss 
  • Compulsive bathing and showering 

Following the hyperemetic phase is the recovery phase, in which patients resume normal eating patterns and symptoms begin to improve. 

Is CHS deadly?

CHS can cause extreme discomfort, but dying from this syndrome is extremely rare. As of this date, less than ten deaths have been attributed to CHS, out of an estimated 2.7 million cases. As such, it’s important for cannabis consumers to be mindful of the symptoms of CHS and to seek medical attention if they suspect that they may have the condition.

What Causes Cannabinoid Hyperemesis Syndrome?

Researchers believe that cannabinoid hyperemesis syndrome is brought about by heavy cannabis consumption. In most cases, patients have been consuming cannabis daily or nearly daily for long periods of time—often several years—before the onset of symptoms. So far, there is little to no evidence of CHS occurring without the patient having a history of heavy cannabis usage. The numbers indicate that developing CHS is very uncommon even among those who consume cannabis regularly. 

It is unclear exactly why cannabis causes CHS, especially considering that cannabis is often recommended as a way to prevent nausea and vomiting. One theory regards the effect that cannabis has on the digestive tract. While THC has been shown to send anti-nausea signals to the brain, the opposite may be true for the digestive system. It’s possible that prolonged cannabis consumption can weaken the endocannabinoid response to THC in the brain. Subsequently, the effects of cannabis on the digestive tract may become more apparent, resulting in the symptoms of CHS.

Research into how cannabis interacts with the gastrointestinal tract, and how this may affect CHS, is ongoing. This disease was discovered roughly fifteen years ago and as time goes on, we will likely learn more about its causes. 

Is CHS genetic?

Since only a small portion of frequent cannabis consumers appear to develop CHS, it’s possible that genetics may play a role. Research suggests that some patients may have genetic variations in cannabinoid metabolism that can lead to excessive levels of nausea. Unfortunately, not enough research has been done in this area to determine what makes some cannabis consumers more susceptible than others. 

Can CBD cause CHS?

The relationship between CBD and cannabinoid hyperemesis syndrome is unclear, but it’s possible that it may contribute to the condition in a similar way that THC does. There is a chance that large doses of CBD may increase symptoms of abdominal pain, nausea, and vomiting in those with CHS. For that reason, it is recommended that anyone suffering from this condition avoids CBD products as well as THC products.

Can Cannabinoid Hyperemesis Syndrome Be Treated?

There are a variety of ways to alleviate symptoms of cannabinoid hyperemesis syndrome, but the most important step is to stop all cannabis consumption. Cannabis cessation is recommended as the primary treatment for CHS, as symptoms usually clear up shortly afterwards. 

Compulsive bathing and showering in hot water is commonly associated with CHS as it can temporarily relieve symptoms, but this is not a long-term fix. Similarly, over-the-counter treatments for preventing nausea are usually not effective at treating the illness, according to a 2015 guide for practicing clinicians.

Depending on the severity of a patient’s symptoms, they may require additional treatment on top of ending cannabis consumption. In some rare cases, those with severe symptoms during the hyperemesis phase may require hospitalization, where they may receive treatment for dehydration or stomach inflammation. 

Is CHS permanent?

CHS is not permanent in the sense that most people will recover from symptoms once they stop consuming cannabis products. However, once a patient develops CHS, any future cannabis consumption may prompt a recurrence of the condition. A study of 98 CHS patients found that the only patient whose symptoms were not improving upon a follow-up medical visit had started consuming cannabis again. Therefore, long-term cessation of cannabis is recommended to prevent future flare-ups. 

How long does it take to recover from CHS?

Recovery time for CHS varies from patient to patient, but research suggests that once patients are cleared to leave the emergency department or hospital, they usually do not have to return as long as they stop consuming cannabis products. 

Typically, the hyperemetic phase of CHS—when symptoms are at their strongest—lasts for about 24-48 hours. Afterwards, patients will enter the recovery phase, which may last for weeks or months. During this time, symptoms subside and patients will regain their appetite. If a patient consumes cannabis again after recovering from CHS, there is a high potential that symptoms will return and they will re-enter the prodromal phase of the illness.

Learn More About Safe and Responsible Cannabis Consumption

Ultimately, a lot of questions about cannabinoid hyperemesis syndrome remain unanswered as scientists continue to research the condition. While CHS is a serious illness that all cannabis consumers should be aware of, it’s important to keep in mind that if you consume cannabis in moderation, your risk for developing CHS is extremely low.

Heavy cannabis consumers who believe they may have CHS should stop cannabis use and consult their healthcare provider about their symptoms. If you feel unwell or anxious after consuming cannabis but are not a long-term or frequent consumer, read more about what to do if you take too much.

To learn more about responsible cannabis use, visit our resource center. Additionally, we recommend becoming a Happy Valley insider to stay informed on new products and cultivars at our Massachusetts dispensaries.

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