A Mysterious Syndrome: What Is Cannabinoid Hyperemesis Syndrome (CHS)?

Written by Cathy Rozyczko — Edited by Jason Brett on September 27, 2021

Cannabinoid hyperemesis syndrome (CHS) is a true mystery. It can pop up out of nowhere for chronic cannabis users, and typically doesn’t go away.

The symptoms of CHS include nausea, vomiting, and abdominal pain or cramps. Many experts believe its occurrence is linked to an increase in the availability of highly potent indoor cannabis. You may be wondering if cannabis today is really that different from the cannabis of years past—in short, it is.

For context, the average potency of cannabis in 1993 was 3.4% THC. Present day, that potency has jumped to upwards of 30% THC in many strains.

Who Gets Cannabinoid Hyperemesis Syndrome (CHS)?

Individuals who are diagnosed with CHS have typically been smoking cannabis 3-5 times daily for 5-15 years on average. Although, it is worth noting that an estimated one-third of cases develop in those who have been using for less than a year.

Various theories exist on the cause of CHS. One of the more prominent theories suggests the condition is due to a genetic polymorphism, or genetic mutation, in the CYP450 gene. The CYP450 enzymes are the enzymes that metabolize cannabinoids, and a mutation could potentially cause an accumulation of pro-emetic (nausea-inducing) cannabinoids and their metabolites.

Individuals with CHS often present emergency-level symptoms several times before their mysterious condition is discovered.

Adding to the confusion, CHS is often misdiagnosed as cyclic vomiting syndrome (CVS), a condition with nearly identical symptoms. The way to differentiate between the two is by knowing that people with CVS almost always have concomitant anxiety, depression, and a high prevalence of migraines. Additionally, gastric emptying is accelerated in patients with CVS but delayed in those with CHS.

What Are the Symptoms of CHS?

Cannabinoid hyperemesis syndrome is divided into three phases: prodromal, hyperemetic, and recovery.

The Prodromal Phase

The prodromal phase can last for months or years. In this phase, individuals can experience morning sickness and abdominal discomfort. Many people turn to cannabis to alleviate these very symptoms, which is why it can sometimes be so difficult to identify the causes and connect all the dots.

The Hyperemetic Phase

The hyperemetic phase usually lasts between 24 to 48 hours, and during this period patients tend to exhibit intense nausea and vomiting, often described as overwhelming and incapacitating. Along with this nausea and vomiting comes abdominal pain and dehydration, which may be severe enough to require IV fluids. Additionally, many individuals report weight loss from frequent vomiting and inability to eat or drink.

The Recovery Phase

The recovery phase can last days, weeks, or months, and is associated with normal eating and relative wellness. It seems that cessation of cannabis use is the only way to alleviate symptoms of CHS.

Some patients have reported relief from pharmaceuticals such as lorazepam or haloperidol, but these medications are not without their own risks, making this a path most people are not interested in pursuing.

Treating Cannabinoid Hyperemesis Syndrome

If you or someone you know is experiencing symptoms that sound like cannabinoid hyperemesis syndrome, speak to a doctor. Doing so will help verify whether you have this mysterious syndrome, or something else.

Giving up cannabis completely is the only way to truly find relief from CHS. Symptoms can disappear quickly, but you can expect a rapid return if you start to use again.

Unfortunately, it appears that CBD, especially at high doses, may be one of the cannabinoids that play a role in the development of CHS. So, if you are not microdosing CBD oil or using a low CBD concentration, you might consider reducing or eliminating your use and see if symptoms clear.

Taking a hot shower or bath has been a proven method for relieving the symptoms of CHS. The exact reason for this is unknown but it may have something to do with the transient receptor potential vanilloid subtype 1 (TRPV1). TRPV1 is impacted by cannabis use, heat, and capsaicin, the compound that gives chili peppers their burn. It is believed that cannabis use decreases TRPV1 signaling and reduces gastric motility, and the warm temperature of a hot bath or shower help to counteract these effects.

Interestingly, one case study found that a topical application of capsaicin improved CHS symptoms both in hospital and with continued use upon release. One case study isn’t enough to suggest that capsaicin can be a cure for CHS, but with more research, it may point to a potential remedy.

In summary, discontinuing cannabis use is, for now, likely the best path forward, but for help with CHS symptoms as they are presenting, hot showers and capsaicin may help.

CHS remains something of a mysterious syndrome. Having only recently been discovered, many health care professionals may not instantly recognize the symptoms. It is important that you are honest with your doctor. If you are using cannabis, disclosing that could be the key to receiving a diagnosis and finding relief.

The more people that present honestly with CHS, the less mysterious the condition will become and the faster a sure-fire remedy will be found.

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