Cannabis has long been used to help with stomach problems like vomiting or nausea[1]. However, science has now discovered that in some rare and unique cases cannabis can actually have the complete opposite effect. It is a condition known as Cannabinoid Hyperemesis Syndrome.

It was in 2004 that a study conducted in Australia[2] first described this syndrome, being further clarified with the clinical diagnostic criteria of CHS in 2009. Before this, most patients suffering from CHS were wrongly diagnosed with Cyclic Vomiting Syndrome or CVS, resulting in a number of visits to the emergency room but without a long-term solution or cure.


The syndrome seems to develop in heavy cannabis users that have been using cannabis excessively for a long period of time. The onset of the symptoms may actually be very long; a study done[3] by the Philadelphia PA showed that the average time before symptoms appeared was around 16 years. The earliest that was found had developed the syndrome after three years of heavy daily cannabis use.

The symptoms can be separated into three phases: a pre-emetic phase, a hyper emetic phase, and ultimately, recovery. In the pre-emetic phase, symptoms will begin to appear, although usually still mild. This phase can last for several years. The first symptoms to appear are usually a fear of vomiting, abdominal discomfort and nausea, usually leading to an increase in cannabis consumption because of the belief that the cannabis will alleviate the nausea.

vomiting syndrome CVS cannabis excessive use

Next is the hyper emetic phase, which is the peak of the symptoms. It is usually shorter, lasting between 24 and 48 hours during which the patient will experience sudden bouts of intense vomiting and nausea. The vomiting can actually build up to 5 times per hour and will coincide with dehydration, abdominal pain and weight loss.

The last phase is the recovery phase in which the symptoms disappear, and patients start to regain weight because their appetite returns. The recovery phase can last months, but because most patients return to their old cannabis consumption, it is only a matter of time before the symptoms reappear and the patient relapses.


Most patients report taking several hot baths and showers a day to very temporarily help relief the symptoms. Treatment with lorazepam or haloperidol has also proven to help with the nausea and vomiting. This is all just to help with the symptoms. The only known way around the syndrome is for sufferers to halt cannabis consumption altogether.

External Resources:
  1. Is Marijuana an Effective Treatment for Reducing Nausea and Vomiting from Chemotherapy? - Medical Marijuana -
  2. Cannabinoid hyperemesis: cyclical hyperemesis in association with chronic cannabis abuse
  3. Cannabinoid Hyperemesis Syndrome
This content is for educational purposes only. The information provided is derived from research gathered from external sources.

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