Cannabinoid hyperemesis syndrome

Cannabinoid hyperemesis syndrome (CHS) is recurrent nausea, vomiting, and cramping abdominal pain that can occur due to prolonged, high-dose cannabis use. These symptoms may be relieved temporarily by taking a hot shower or bath. Complications are related to persistent vomiting and dehydration which may lead to kidney failure and electrolyte problems.

Weekly cannabis use is generally required for the syndrome to occur; synthetic cannabinoids can also cause CHS. The underlying mechanism is unclear, with several possibilities proposed. Diagnosis is based on the symptoms, as well as the history of cannabis use (including a urine screen test if necessary). 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. Two weeks (or possibly up to 3 months) may be required to see a benefit. Treatments during an episode of vomiting are generally supportive in nature (e.g., hydration). There is tentative evidence for the use of capsaicin cream on the abdomen during an acute episode.

Another condition that presents similarly is cyclic vomiting syndrome (CVS). The primary differentiation between CHS and CVS is that cessation of cannabis use only resolves CHS. CVS does not resolve with the cessation of cannabis use. 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.