Cannabinoid hyperemesis syndrome

Cannabinoid hyperemesis syndrome (CHS) is recurrent nausea, vomiting, and cramping abdominal pain that can occur due to cannabis use.

CHS is associated with frequent (weekly or more often), long-term (several months or longer) cannabis use; synthetic cannabinoids can also cause CHS. The underlying mechanism is unclear, with several possibilities proposed. Diagnosis is based on the symptoms; a history of cannabis use, especially persistent, frequent use of high-dose cannabis products; and ruling out other possible causes of hyperemesis (persistent vomiting). The condition is typically present for some time before the diagnosis is made.

The only known curative treatment for CHS is to stop using cannabis. Symptoms usually remit after two weeks of complete abstinence, although some patients continue to experience nausea, cyclic vomiting, or abdominal pain for up to 90 days. Treatments during an episode of vomiting are generally supportive in nature (one example being hydration). There is tentative evidence for the use of capsaicin cream on the abdomen during an acute episode.

Frequent hot showers or baths are both a possible sign (diagnostic indicator) of CHS, and a short-term palliative treatment (often called hot water hydrotherapy in the medical literature).

Another condition that presents similarly is cyclic vomiting syndrome (CVS). The primary differentiation between CHS and CVS is that cessation of cannabis use resolves CHS, but not CVS. Another key difference is that CVS symptoms typically begin during the early morning; predominant morning symptoms are not characteristic of CHS. Distinguishing the two can be difficult since many people with CVS use cannabis, possibly to relieve their symptoms.

The syndrome was first described in 2004, and simplified diagnostic criteria were published in 2009.