Human health is complex and diagnostic tools and their limitations, so missing a diagnosis is sometimes unavoidable. But every missed diagnosis has the potential to cause harm to a patient, as is demonstrated by a dangerous trend I’ve noticed within emergency departments: a tendency to attribute symptoms too readily to cannabis hyperemesis syndrome (CHS) without adequate diagnostic work-up.
Cannabis and various cannabinoid-based products have become increasingly accessible across the United States and internationally, both for medical and recreational use. This growing availability and social acceptance have led to some combination of increased use in the community and/or increased willingness on the part of patients to admit such use to health professionals.
To the extent that there may be increased actual use, it is likely that we are/will see an increase in cannabis-related health complications. Among these, CHS — a condition characterized by cyclical vomiting in long-term, heavy users of cannabis — is being recognized more frequently.
CHS, while real and certainly debilitating for those who suffer from it, is still relatively uncommon, though the actual national prevalence is unknown, and requires a careful diagnosis. The hallmark symptoms include recurrent nausea, intractable vomiting, and abdominal pain, often temporarily relieved by hot showers or baths. The only known long-term treatment is complete cessation of cannabis use.
My work as a practicing cannabinoid specialist hinges on not only providing guidance and access to cannabis-based medicines, but on mitigating and responding to the risks. After nearly 15 years of practicing this type of medicine exclusively, I have seen both the reward of patients’ quality of life improved, and the risks of incautious use. Like all medications, cannabinoids have risk, and the clinicians’ job is to use these medications carefully to maximized benefit and minimize risk.
As CHS has become more widely acknowledged, this broader awareness has led to a new risk: overdiagnosis. Clinicians, particularly in fast-paced environments like EDs, may find themselves attributing any vomiting in a cannabis user to CHS. This sort of knee-jerk thinking is emblematic of the cognitive bias known as “anchoring” — wherein a clinician fixates on an initial piece of information (in this case, cannabis use) and fails to consider alternative or concurrent diagnoses.
Over the past several years, an alarming number of anecdotal reports and my personal informal polling of colleagues suggest that ED physicians have developed a certain antipathy toward patients they perceive as “drug users,” including those who use cannabis and have been diagnosed with CHS. Some ED providers have openly expressed frustration with these patients, viewing their illness as self-inflicted or non-urgent, clogging up the already overburdened emergency care system.
A recent case report demonstrates this failure in clinical judgment. In the case presented, a 17-year-old patient with a history of cannabis use exhibited persistent vomiting, which was immediately attributed to CHS.
However, further investigation revealed a diagnosis of superior mesenteric artery (SMA) syndrome — a rare and potentially life-threatening condition wherein the duodenum is compressed between the aorta and the superior mesenteric artery, causing severe gastrointestinal symptoms. The premature conclusion of the diagnosis of CHS led to a significant delay in proper diagnosis and treatment (though the paper is unclear about the exact duration), illustrating how harmful anchoring bias can be.
This case also shines a light on a broader cultural issue within medicine. There remains a pervasive stigma around cannabis use, even in states where it is fully legal and socially normalized. Many physicians receive little to no formal education on cannabis and its pharmacology during medical school, and what little information was provided is often colored by decades of prohibitionist rhetoric. As a result, many clinicians feel ill-equipped or even resistant to engaging with cannabis-related cases.
We must also consider how this affects patients. Being labeled with CHS may not only delay diagnosis of more serious conditions but can also result in significant psychological harm. Patients may feel dismissed or judged rather than supported and understood. They may also become less likely to seek future medical care, fearing ridicule or disbelief. This undermines the therapeutic relationship and compromises public trust in medical professionals.
Renowned Harvard Medical School educator Marshall A. Wolf once said to me, “You can’t find what you aren’t looking for.” This simple yet profound statement should be a guiding principle for all clinicians. It’s a reminder that diagnostic success is predicated on open-mindedness, curiosity, and humility. If we approach each patient encounter with these values, we are more likely to arrive at the correct diagnosis and provide the care our patients truly need.
In the age of expanding cannabis legalization and use, clinicians must catch up with the science and nuance of cannabinoid medicine. Education must be improved — in medical school curricula as well as in continuing education for practicing physicians. Institutions should offer clear guidelines on how to accurately diagnose CHS, with an emphasis on ruling out other causes of vomiting first. We must also train physicians to recognize and counteract their own implicit biases, especially in relation to substance use.
While CHS is a valid and important diagnosis, its overuse — especially in ED settings — reflects a dangerous oversimplification of patient care. By reflexively attributing vomiting to cannabis use, physicians may miss serious, even life-threatening conditions like SMA syndrome. We must confront our biases, invest in better education, and most importantly, uphold our duty to deliver compassionate, evidence-based care. Only then can we ensure that our patients — regardless of their cannabis use — are treated with the respect and thoroughness they deserve.