Cannabis Hyperemesis Syndrome: How the Same System That Prevents Nausea Can Also Cause It

The endocannabinoid system produces biphasic effects: acute cannabis use is antiemetic, but chronic heavy use can trigger a proemetic response leading to CHS. The review outlined key differences between CHS and cyclic vomiting syndrome and described the pathophysiology involving desensitization of CB1 receptors in the gut.

Narrative review synthesizing evidence on the endocannabinoid system's role in CHS pathophysiology, clinical features, diagnosis, treatment, and differentiation from similar conditions, particularly cyclic vomiting syndrome.

CHS is frequently misdiagnosed because it shares symptoms with many gastrointestinal conditions. Understanding the biphasic mechanism explains the counterintuitive finding that an antiemetic substance can cause severe vomiting, helping clinicians recognize and properly diagnose CHS.

As CHS becomes more common, the medical community needs clear frameworks for diagnosis and treatment. The distinction from cyclic vomiting syndrome is particularly important because treatments differ, and misdiagnosis delays appropriate care.

Narrative review format without systematic search methodology. CHS pathophysiology is still not completely understood. The review relied on case reports and small studies given the limited controlled research on CHS.