The Importance of Accurate Drug Use History in Diagnosing and Managing Cannabinoid Hyperemesis Syndrome: A Case Report.

Cannabinoid hyperemesis syndrome (CHS) is a paradoxical condition characterized by recurrent episodes of nausea, vomiting, and abdominal pain in chronic cannabis users. Despite the increasing legalization and widespread use of cannabis, CHS remains underdiagnosed, often leading to unnecessary diagnostic tests and ineffective treatments. The syndrome is marked by symptom relief through hot baths, a behavioral pattern that can aid in its identification.We report a case of a 29-year-old male with a five-year history of recurrent vomiting and significant weight loss. The patient had multiple emergency department visits and was misdiagnosed with anxiety disorder due to the absence of significant findings on diagnostic tests. His condition was further complicated by a concurrent infection, which delayed the clinical suspicion of CHS. A detailed assessment revealed a prolonged history of daily cannabis use and symptom relief through compulsive hot bathing. Upon cessation of cannabis use and symptomatic treatment with mirtazapine, quetiapine, and lorazepam, the patient showed complete resolution of symptoms and remained asymptomatic.This case highlights the diagnostic challenges of CHS and underscores the importance of targeted questioning about cannabis use in patients presenting with cyclical vomiting. Clinicians should maintain a high index of suspicion, especially in cases resistant to conventional antiemetic therapy. Early recognition and patient education regarding cannabis cessation are critical to preventing recurrence and improving long-term outcomes.