What is Cannabis Hypermesis Syndrome?

What is Cannabis Hypermesis Syndrome?

Published on 12/27/20

When cannabis enters the body there are myriad ways the cannabinoids it contains like tetrahydrocannabinol (THC), cannabidiol (CBD) affect change. The body's endocannabinoid system (ECS) is filled with cannabinoid receptors to regulate key functions like mood, appetite, reaction to pain and more. THC attaches to receptors in the brain and the body that interrupt the body's homeostasis and produce that high feeling. If the strain is higher in CBD content, that dynamic cannabinoid will ease some of the psychoactive effects of the THC and keep the ECS in a more balanced state. All of this regulates the contradictory feelings we can experience with weed such as relaxed vs. anxious, attuned vs. spaced out, lethargic vs. energetic and so on.


The brain is not the only part of the body that the cannabinoids in marijuana influences. The gastrointestinal system and digestive tract also have molecules that bind with THC. In fact, THC and THCa affect the lower esophageal sphincter (LES) that controls when food transfers from the esophagus to the stomach. This is normally not a bad thing; the cannabinoids often alter the molecules in manners that assist with acid reflux irritations and more severe ailments like gastroesophageal reflux disease (GERD). Unfortunately, in some cases, constant long-term marijuana use can change the way the affected molecules respond and cause the onset of the extremely distressing cannabis hyperemesis syndrome - also known as cannabinoid hyperemesis syndrome (CHS).

What is CHS?

CHS is a condition that produces repeated and usually severe bouts of vomiting from the long-term use of cannabis. The brain normally helps prevent nausea and vomiting and increases appetite. But, in the digestive tract of certain individuals, weed can have the opposite effect and increase the likelihood of nausea. Thankfully, very few people develop CHS and those that do normally have smoked weed at least once a day for several years.
The first study of CHS illness was published in 2004 by researchers in Australia. Their paper was the result of the examination of regular and long-term cannabis users who were experiencing unusually intense and chronic bouts of vomiting. Subsequent studies have led researchers, physicians and healthcare providers to delineate the symptoms of CHS and how it affects the body into three distinct phases.

Cannabinoid Hyperemesis Syndrome Symptoms and Phases

Prodromal Phase


The symptoms of this initial phase are often not terribly severe and can prompt additional use of cannabis in a vain effort to curb the onset of nausea. Obviously, this simply inflames the situation. The Prodromal Phase can last anywhere from a few months to several years.


  • Abdominal Pain
  • Early Morning Nausea
  • Fear of Vomiting

Hyperemetic Phase


This is when things really begin to get ugly. The nausea increases in intensity and the person experiencing the symptoms often begins to take very hot showers in order to ease the amount and severity of the vomiting. The reason for this seemingly odd behavior is that heat affects a region in the brain called the hypothalamus. This part of the brain in turn regulates both body temperature and vomiting. A hot shower can provide a temporary respite from the pain. The Hyperemetic Phase normally continues until the individual quits consuming marijuana. The only truly effective cannabis hyperemesis syndrome treatment is cessation.


  • Intense Nausea and Repeated Episodes of Vomiting
  • Acute Abdominal Pain
  • Dehydration
  • Lack of Appetite and Weight Loss

Recovery Phase 

During the recovery phase, things return to normal. This can occur within 12 hours or might take as long as three weeks. Studies show that anyone who has suffered from CHS and begins cannabis use again will start another cycle of the syndrome so it is imperative not to return to any type of marijuana use. 


  • Normal Eating and Digestion 
  • Weight Gain
  • Regular Bathing Habits

Some people with CHS might not be diagnosed for several years. Being upfront  with your healthcare provider about your daily marijuana use can speed up the diagnosis. You might need to stay in the hospital to treat dehydration from CHS.

What Causes Cannabinoid Hyperemesis Syndrome?


There continues to be debate among experts about the causes of CHS and why it presents in some people but not in others that have been daily cannabis users for decades. There is some basis for the theory that it could be related to a genetic trait, but there is also an argument that it is simply the result of increasing cannabis use over time coupled with ballooning THC amounts in smokable marijuana products. Other researchers believe that a hypothalamic-pituitary-adrenal (HPA) axis abnormality might be to blame simply because that axis controls so much of how the body operates on a neurological and functional level. Whatever the cause, cannabinoid hyperemesis syndrome treatment can only be prescribed if it is properly diagnosed, so if you are experiencing symptoms and are a chronic weed user, let your physician or healthcare provider know immediately so you can receive the proper CHS treatment. 

These are some of the tests that can rule out other causes of constant vomiting and direct physicians to a proper plan of care for cannabis hyperemesis syndrome.

  • Pregnancy
  • Drug Screen
  • Anemia
  • Liver and Pancreas Enzymes
  • Abdominal CT Scan
  • Head CT Scan
  • Upper Endoscopy

Although there have only been a few documented cases of cannabinoid hyperemesis syndrome death, the long-term effects of not properly dealing with CHS weed symptoms can be catastrophic. Seizures, kidney failure, shock and cerebral edema are just a few of the complications that can arise.

Have you ever thought that you might have CHS or been diagnosed with CHS? Take a moment to tell us your story in the comments section below.

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