Proposal to Add a New ICD-11 Category: Cannabis-Induced Hyperemesis With
Delirium
Submitted to:
Centers for Disease Control and Prevention (CDC)
National Center for Health Statistics (NCHS)
ICD Coordination and Maintenance Committee
Date: November 10, 2025
1. Proposal Summary
This proposal requests creation of a new ICD-11 category
under Disorders due to use of cannabis (6C41) to capture the co-occurrence of
cannabis-induced hyperemesis and delirium as a distinct clinical entity. The
proposed code would enable accurate epidemiologic tracking of
neuro-gastrointestinal toxicity from tetrahydrocannabinol (THC) exposure,
particularly among older adults users consuming high-dose edible or
combined oral/inhaled cannabis products.
2. Proposed New Entity
Proposed Title: 6C41.Y — Cannabis-Induced Hyperemesis With
Delirium
Parent Category: 6C41 — Disorders due to use of cannabis
Proposed Type: New distinct entity (combination disorder)
Synonyms: Concurrent cannabis-induced hyperemesis and
delirium; THC toxicity with vomiting and delirium; Cannabis-related
hyperemesis-delirium complex.
3. Rationale for Inclusion
Both cannabis-induced hyperemesis syndrome (CHS) and
cannabis-induced delirium are recognized in ICD-11, yet clinical reports
increasingly demonstrate that these conditions can occur simultaneously. This
co-occurrence represents a distinct pathophysiologic syndrome characterized by
severe vomiting, dehydration, and altered mental status linked to THC toxicity.
The current ICD-11 structure requires dual coding (6C41.5 and MD90.1), which
hampers accurate reporting and surveillance.
Clinically, CHS and delirium share overlapping etiologic
factors—THC accumulation, dehydration, metabolic stress, and age-related
pharmacodynamic sensitivity. Older adults and new cannabis users represent an
emerging risk population with unique vulnerability to combined
neuro-gastrointestinal toxicity.
4. Epidemiologic Relevance
Cannabis-induced hyperemesis syndrome is increasingly
reported globally with legalization and higher potency formulations. Delirium
due to cannabis toxicity, though rare, is documented particularly among elderly
users or those ingesting edibles. The overlap of both syndromes in one episode,
though underreported, likely contributes to emergency department visits labeled
as 'nausea and confusion after cannabis use'. A unique code would improve
public health surveillance and facilitate research into THC-related systemic
and neuropsychiatric complications.
5. Case Example (Index Case)
A 75-year-old woman ingested 40 mg of oral THC and smoked
cannabis the same day, developing repeated vomiting of green bile followed by
expressive aphasia, disorientation, and confusion lasting 36 hours. She was
mildly dehydrated but otherwise stable. Both hyperemesis and delirium resolved
after intravenous fluids and observation. No structural or metabolic cause was
found. (Behar D. Concurrent Cannabis-Induced Hyperemesis and Delirium in an
Older Adult: Case Report, 2025.)
6. Proposed ICD-11 Structure
Code: 6C41.Y — Cannabis-Induced Hyperemesis With Delirium
Description: A disorder characterized by the simultaneous occurrence of severe
nausea and vomiting (hyperemesis) and an acute confusional or delirious state,
temporally related to cannabis use. Symptoms typically resolve after cessation
of cannabis and supportive therapy.
Hierarchical placement:
→ 6C4 — Mental and behavioural disorders due to psychoactive substance use
→ 6C41 — Disorders due to use of cannabis
→ 6C41.Y — Cannabis-Induced Hyperemesis With Delirium
Exclusions:
- 6C41.5 Cannabis-induced delirium (without vomiting)
- MD90.1 Vomiting, unspecified
- 8A80.4 Cyclic vomiting syndrome
7. Supporting Evidence
1.
Allen JH, de Moore GM, Heddle R, Twartz JC.
Cannabinoid hyperemesis: cyclical hyperemesis in association with chronic
cannabis abuse. Gut. 2004;53(11):1566–1570.
2.
Lapoint J, Meyer S, Yu CK, Koenig KL,
Thihalolipavan S, Anderson IB. Cannabinoid hyperemesis syndrome: public health
implications and a novel model treatment guideline. West J Emerg Med.
2018;19(2):380–386.
3.
Sorensen CJ, DeSanto K, Borgelt L, Phillips KT,
Monte AA. Cannabinoid hyperemesis syndrome: diagnosis, pathophysiology, and
treatment—a systematic review. J Med Toxicol. 2017;13(1):71–87.
4.
Hall W, Degenhardt L. Adverse health effects of
non-medical cannabis use. Lancet. 2009;374(9698):1383–1391.
5.
Stark T, Pettit A, Nystrom K, Hall J. Delirium
following ingestion of cannabis edibles in an elderly patient: a case report.
Clin Gerontol. 2020;43(8):123–129.
8. Public Health and Policy Impact
• Improved surveillance: Enables tracking of combined
neuropsychiatric and gastrointestinal toxicity linked to cannabis.
• Enhanced clinical recognition: Encourages integrated management of delirium
and hyperemesis as a unified syndrome.
• Geriatric safety: Identifies a vulnerable subgroup at risk from oral and
combined THC formulations.
• Research facilitation: Supports pharmacovigilance, outcomes tracking, and
coding consistency across datasets.
9. Requested Action
The CDC/NCHS and WHO-FIC Update Committee are requested to:
1. Approve creation of ICD-11 code 6C41.Y — Cannabis-Induced Hyperemesis With
Delirium.
2. Include the entity in the ICD-11 2026 Update Cycle.
3. Issue coding guidance to emergency medicine, psychiatry, and toxicology
providers.
