Cannabinoid hyperemesis syndrome (CHS)

Overview

Cannabinoid Hyperemesis Syndrome (CHS) is a condition characterized by recurrent episodes of severe nausea, vomiting, and abdominal pain in individuals who use cannabis frequently over a prolonged period. It is a paradoxical reaction, as cannabis is typically known for its anti-nausea properties. CHS is most often seen in long-term, daily cannabis users and can lead to dehydration, weight loss, and repeated emergency room visits. One of the distinguishing features of CHS is the temporary relief of symptoms through hot showers or baths.

Causes

CHS is believed to be caused by prolonged and heavy cannabis use, although the exact mechanism is not fully understood. Theories suggest that chronic exposure to high levels of cannabinoids may disrupt the endocannabinoid system, which regulates nausea, vomiting, and digestion. Over time, this disruption may cause the body to react adversely, leading to hyperemesis (severe vomiting). Genetic factors and individual susceptibility may also play a role in the development of CHS.

Symptoms

CHS progresses through three stages:

• Prodromal phase: May last months or years, marked by early morning nausea, anxiety, and abdominal discomfort without vomiting. Many individuals continue cannabis use during this phase, believing it helps with nausea.

• Hyperemetic phase: Characterized by intense and persistent nausea, repeated vomiting, abdominal pain, and loss of appetite. Episodes can last for days and often lead to dehydration and electrolyte imbalances. Patients frequently find relief by taking long, hot showers or baths.

• Recovery phase: Begins after cannabis use is stopped. Symptoms gradually resolve, and patients return to normal health. The condition can recur if cannabis use resumes.

Additional symptoms may include weight loss, fatigue, muscle cramps, and frequent hospital visits due to severe dehydration.

Diagnosis

CHS is diagnosed based on clinical history, symptoms, and exclusion of other possible causes of nausea and vomiting. Diagnostic steps may include:

• Detailed history: Long-term, frequent cannabis use (usually daily or near-daily for several months or years)

• Symptom pattern: Recurrent vomiting relieved by hot showers or baths

• Physical exam and lab tests: To rule out infections, gastrointestinal disorders, or metabolic conditions

• Imaging studies: Such as ultrasound or CT scan to rule out structural problems

• Response to cannabis cessation: Symptom improvement after stopping cannabis use supports the diagnosis

Treatment

The only definitive treatment for CHS is the complete cessation of cannabis use. Other supportive treatments may help manage symptoms during acute episodes:

• Stopping cannabis use: Permanent discontinuation is the most effective and curative treatment

• IV fluids and electrolyte replacement: To treat dehydration and imbalances during hyperemetic episodes

• Antiemetic medications: Sometimes used, though often less effective in CHS compared to other causes of nausea

• Pain management: For abdominal discomfort, typically using non-opioid options

• Hot showers or baths: Provide temporary relief of symptoms during episodes

• Capsaicin cream: Applied topically to the abdomen in some cases to mimic the effects of heat

• Psychological support: Counseling or addiction therapy may be beneficial for long-term cannabis cessation

Prognosis

The prognosis for individuals with CHS is excellent if cannabis use is discontinued. Most patients experience complete resolution of symptoms within days to weeks after stopping cannabis. However, if cannabis use continues or is resumed, symptoms are likely to return. Education and awareness are crucial, as many patients initially do not associate cannabis with their symptoms. Long-term recovery depends on sustained cannabis abstinence and supportive medical and behavioral care.