Cannabinoid Hyperemesis Syndrome: An Emerging Challenge in Patient Care

Published: August 2025

Cannabinoid Hyperemesis Syndrome (CHS) is a condition increasingly observed among long-term users of cannabis.^1,2 Despite cannabis being proposed for its antiemetic effects, this very same compound has been linked to CHS, a condition marked by recurring nausea, vomiting and abdominal pain, often severe enough to require emergency medical care.^1,3

Increasing awareness and understanding of CHS among both patients and clinicians may play a key role in promoting safer, more effective treatment outcomes as early recognition and management of this syndrome may reduce the risk of potentially serious sequelae.^1,2,4

What is Cannabinoid Hyperemesis Syndrome?

Cannabinoid Hyperemesis Syndrome is a condition characterised by cyclical episodes of nausea, intractable vomiting, and abdominal pain following prolonged cannabis use.¹ First described in 2004, CHS remains underdiagnosed and often mistaken for other gastrointestinal conditions such as cyclic vomiting syndrome (CVS).^1,3

According to the Rome IV diagnostic criteria, CHS is defined by:

• Stereotypical episodic vomiting similar to CVS in onset and duration
• A history of prolonged cannabis use
• Relief of symptoms with sustained cannabis cessation.⁵

An additional defining feature of CHS is that patients often find relief through taking very hot showers or baths.¹

Whilst the exact pathophysiology of CHS is not yet fully elucidated, it appears to be linked to the overstimulation of CB1 endocannabinoid receptors in the endocannabinoid system (ECS) by the cannabinoid tetrahyrdocannabidiol (THC), leading to changes in the body’s emetic control centres in the central nervous system and brainstem.^1,2 Another proposed mechanism involves THC binding to the TRPV1 (transient receptor potential vanilloid 1) receptors, which is involved in pain and temperature perception and regulation of gut motility.^1,2

Paradoxically, while low doses of cannabis exert antiemetic effects through ECS modulation and hypothalamus-pituitary-adrenal (HPA) axis suppression, chronic use of cannabis containing high-strength THC may have the opposite effect, leading to overstimulation of the ECS — one of the proposed mechanisms behind CHS.^1,3,4

How common is CHS?

The true prevalence of CHS is difficult to ascertain and likely underreported.^1,2

This is partly because CHS symptoms overlap with other conditions, and in some jurisdictions, stigma and legal concerns around cannabis use lead patients to withhold disclosure of their medical cannabis use from healthcare providers.^1,7

However, recent data highlight a growing concern:

• A study in a United States urban hospital estimated that 32.9% of chronic users of cannabis (20+ days/month) met the criteria for CHS, which extrapolates to approximately 2.75 million cases annually in the United States.⁷

In Australia, a six-year retrospective review undertaken at a Melbourne emergency department identified 142 CHS-related visits. The median patient age was 31 years, with nearly 69% male, highlighting its prevalence among younger adults.⁸

With cannabis potency and use increasing worldwide, the incidence of CHS may be expected to rise unless proactively addressed.^1-3

Stages and management of CHS

Patients experiencing CHS typically present to the emergency department whilst demonstrating acute gastrointestinal symptoms.⁷ However, according to the American Gastroenterological Association, CHS progresses through four distinct stages:²

• Prodromal Phase – Early symptoms such as nausea, anxiety, and abdominal discomfort, often lasting months.^2,3
• Hyperemesis Phase – Acute onset of relentless vomiting, abdominal pain, dehydration, and compulsive hot bathing.^2,3
• Recovery Phase – Symptoms improve once cannabis use is stopped.^2,3
• Interepisodic Phase – Asymptomatic period between episodes; symptoms often return with cannabis reinitiation.^2,3

Treatment strategies

There is currently no specific pharmacological treatment for CHS. The current cornerstone of management is immediate and sustained cannabis cessation.^1,9

Other strategies include:

• IV fluids and electrolyte correction to manage dehydration⁹
• Hot showers or baths, which may provide temporary relief¹
• Antiemetics – though many are ineffective in CHS¹
• Capsaicin cream (a TRPV1 agonist) applied topically to the abdomen has shown some benefit in acute settings^1,9

Importantly, failure to recognise and treat CHS can lead to serious complications, including electrolyte and fluid imbalance, renal failure and, in rare cases, death.^1,10,11

Is CHS permanent?

CHS appears reversible with cannabis cessation.¹ Case studies have widely shown that symptoms resolve once cannabis use is stopped.^12,13 However, due to limited long-term studies, it remains unclear whether some individuals may develop persistent or recurring symptoms even after cessation.^12,13

Implications for medical cannabis use

To date, CHS has been primarily associated with chronic recreational use of high-dose THC products.¹⁴ However, as medical cannabis becomes more widespread, and as higher-potency THC formulations become more accessible, it is possible that CHS may be increasingly observed among users of medical cannabis.^1,2,15

Currently, there is insufficient data to draw conclusions about CHS prevalence in patients using medical cannabis. However, the following precautions are advised:

• Educate patients about the signs and symptoms of CHS before initiating treatment.^4,15
• Prescribe the lowest effective dose, especially with high-strength THC products.^4,6
• Consider CBD-dominant options where appropriate, as CBD has not been linked to CHS.¹⁴
• Establish a thorough patient history of cannabis use, including prior and current recreational use, as past heavy use appears to increase risk.^1,4,15

Summary

Cannabinoid Hyperemesis Syndrome represents a growing but still under-recognised adverse consequence of long-term cannabis use.^1,2 While it may seem contradictory that cannabis — which has proposed antiemetic effects — can cause intractable vomiting, this reflects the complex and dose-dependent biphasic nature of cannabinoid pharmacology.⁴

For healthcare professionals, particularly those prescribing medical cannabis, awareness and vigilance are essential.^1,4,15 Patient education, careful product selection, and prompt cessation in response to symptoms could potentially reduce risks and improve patient outcomes.^1,4,14,15

As the legal and medical landscape around cannabis continues to evolve, understanding CHS may be central to ensuring safe and responsible use of this emerging therapy.

Disclaimer: Medical cannabis products may be associated with adverse events. For more information please contact medinfo@saged.com.au. Medical cannabis products are not suitable for use during pregnancy or breastfeeding, for anyone with a history with psychotic disorders, or for those with unstable cardiovascular disease. Treatment for patients under 18 years is recommended under the guidance of a paediatrician. Patients should not drive or operate machinery while being treated with some forms of medical cannabis.