What are the symptoms of Cannabinoid Hyperemesis Syndrome (CHS)?

Symptoms of Cannabinoid Hyperemesis Syndrome (CHS)

Cannabinoid Hyperemesis Syndrome (CHS) is characterized by stereotypical episodic vomiting, nausea, abdominal pain, and compulsive hot water bathing behavior in the context of chronic cannabis use. 1, 2

Key Clinical Features

Core Symptoms

• Cyclic severe vomiting - stereotypical episodes resembling cyclic vomiting syndrome (CVS), occurring at least 3 times annually 1
• Intractable nausea - often resistant to standard antiemetic medications 3
• Abdominal pain - typically diffuse and can be severe 4
• Compulsive hot water bathing - reported in 71-92.3% of patients, this distinctive behavior provides temporary symptom relief 2, 4

Diagnostic Pattern

• Symptoms develop after prolonged cannabis use (typically >1 year before symptom onset) 1
• Frequent cannabis use (>4 times per week on average) 1
• Resolution of symptoms after cannabis cessation (typically within days to weeks) 2
• Symptoms resistant to conventional antiemetic treatments 5, 3

Patient Demographics

• Typically affects younger adults (mean age around 30 years) 1
• More common in males (approximately 69% of cases) 1
• Mean duration of cannabis use before symptom onset is 6.6 years 1
• Daily cannabis use reported in 68% of cases 1

Clinical Course

Phases of CHS

1. Prodromal phase:

   • Morning nausea
   • Abdominal discomfort
   • Fear of vomiting
   • Normal eating patterns maintained

2. Hyperemetic phase:

   • Intense and persistent nausea
   • Repeated episodes of vomiting
   • Abdominal pain
   • Compulsive hot showering/bathing
   • Dehydration and weight loss

3. Recovery phase:

   • Resolution of symptoms after cannabis cessation
   • Return to normal eating patterns
   • Weight gain

Pathophysiological Mechanisms

CHS likely results from dysregulation of the endocannabinoid system due to prolonged, high-dose cannabis use 6. Potential mechanisms include:

• Disruption of CB1 receptors in the brain's dorsal vagal complex (important for emesis control) 1
• Altered hypothalamic-pituitary-adrenal axis function 3
• Dysregulation of the transient receptor potential vanilloid (TRPV1) system, explaining the relief from hot water 6
• Genetic factors may play a role, with mutations in genes affecting neurotransmitters and cannabinoid metabolism (COMT, TRPV1, CYP2C9, DRD2, ABCA1) 7

Clinical Pitfalls and Caveats

• Diagnostic delay is common due to:

  • Low awareness of the syndrome among healthcare providers
  • Patient reluctance to associate cannabis use with symptoms
  • Overlap with other gastrointestinal disorders

• Treatment resistance: Standard antiemetics (5-HT3 or D2-receptor antagonists) are typically ineffective 4

• Recurrence risk: High rate of symptom recurrence with resumed cannabis use, even after prolonged abstinence 2

• Misdiagnosis: Often confused with cyclic vomiting syndrome, gastroparesis, or other gastrointestinal disorders 2

The only definitive treatment for CHS is complete cannabis cessation for at least 6 months 2. Temporary symptom relief may be achieved with benzodiazepines, topical capsaicin, or hot showers/baths 5, 3.