Cannabinoid hyperemesis syndrome (CHS) is a rare but increasingly recognized condition with perplexing symptoms which commonly include, but are not limited to, nausea, vomiting, abdominal pain, and unusual hot bathing behavior. CHS is triggered by heavy and chronic exposure to tetrahydrocannabinol (THC), the primary intoxicating agent of Cannabis sativa. The only known way to stop symptoms of CHS is THC abstinence. To date there is no known cure. Patients may experience residual symptoms for an interval of time after they have stopped using Cannabis.
Is Cannabis Harmful?
It is important to note that for the vast majority of people Cannabis is a safe and versatile medicine, or social agent. It has been used for thousands of years by humans with no known overdose deaths attributed to its use. There are over 450 chemical components in the cannabis plant, many of which are considered therapeutic. In fact, the cannabis plant is one of the most pharmacologically active and safest plants on the planet, promising a gold mine of therapeutic solutions for undertreated conditions. Unfortunately however, for a small group genetically predisposed people, overexposure to THC can make them very sick by triggering CHS.
How Common is Cannabinoid Hyperemesis Syndrome?
Cannabinoid hyperemesis syndrome has largely been an American phenomenon, although it was first identified in Australia. The prevalence of those suffering with CHS is unknown, but estimates have ranged in the medical literature from 350,000 to 2.75 million in the USA. As more people consume cannabis worldwide, it is realistic to expect that the number of those afflicted will increase.
What Do We Know about CHS?
A relatively new phenomenon, CHS until now has been a diagnosis of exclusion often after multiple expensive ER visits, hospital stays and a battery of tests. There are multiple notations in the medical literature of patients who spend $95,000+ for treatment and diagnosis. A survey of 585 self-described CHS patients indicated the following CHS patient profile:
- 74.8% history of regular cannabis use for over 1 year
- 100% experience severe nausea and vomiting
- 100% vomiting recurring in cyclic patterns over months
- 96.8% resolution of symptoms after stopping cannabis
- 92.3% compulsive hot baths/showers with symptom relief
- 72.9% male predominance
- 85.1% experience abdominal pain
- 97.4% at least weekly cannabis use
- 76.6% and history of daily cannabis use
What Causes Cannabinoid Hyperemesis Syndrome (CHS)?
A variety of hypotheses have existed about the cause of CHS. The most popular theories were centered around pesticide poisoning whose symptomatology looks very different from CHS. New data published in July 2021 in the high-ranking peer-reviewed journal Cannabis and Cannabinoids Research written by Russo et al indicates Cannabinoid Hyperemesis Syndrome susceptibility is a function of one’s DNA.
This study matched the CHS patients with individuals who consumed similar amounts of THC but who did not exhibit similar symptoms of withdrawal, had far less history of addiction and had none of the CHS symptoms. Five different genes emerged as statistically significant indicators of CHS. Interestingly, all of the CHS cohort had a minimum of two of the five genes. The discovery of these genetic markers makes it possible to offer a cost-effective screening test available to those who are exhibiting CHS-like symptoms.
Phases of CHS
- Prodomal Phase – may include morning nausea, anxiety, sweating (diaphoresis), flushing (like a hot flash).
- Hyperemetic Phase – includes abdominal pain, nausea, vomiting, compulsive hot-water bathing that may monopolize the patient’s daily activity.
- Recovery Phase – requires ongoing abstinence from cannabis. Symptom relief is generally immediate after THC cessation but varies in degree of relief and can take up to a year for full relief. Re-exposure to THC initiates the cycle.
DNA Susceptibility Tests
This DNA screening test is now available. (Click here to order one.) Patients are encouraged to order the test through their physician as a part of the diagnostic process. An advantage to the patient for doing so is that the test is more likely to be covered by insurance and physicians can help the patient make sense of the results and suggest best next steps for relief and onward care.
The test will identify if you have the genetic markers associated with CHS. As more people take the test, a deeper understanding of CHS will emerge, which researchers hope will ultimately lead to more definitive diagnosis and better treatment options, and increase our understanding of the disorder.
What is Next in CHS Research?
Additional questions remaining for science to answer are:
- How do the different CHS-related gene combinations impact the constellation and severity of symptoms?
- Do the different CHS-related gene combinations respond better to one medication than another for symptom management?
- Is it possible for those who have CHS or a subset of this population to utilize cannabinoids and other components of the Cannabis plant to manage CHS and/or other medical conditions if those preparations are devoid of THC?
Myths of Cannabinoid Hyperemesis Syndrome
CHS patients are often treated as they are crazy or that their issues are psychosomatic. Nothing could be further from the truth! CHS is real and those who have it suffer greatly. Because CHS has previously been an enigma, hypothesis’ have abound about what could be causing CHS.
Prior to having conclusive scientific evidence that CHS susceptibility is rooted in one’s genes and triggered by THC exposure, people have strongly resisted the theory that THC-exposure was the cause. Speculation into the cause of cannabinoid hyperemesis has included theories that pesticides or neem oil could be the problem. One letter to the editor in an online medical journal forum speculated that it was caused by plant viruses and viroid’s. None of these things seem to be true given recent scientific investigation.