Cannabinoid Hyperemesis Syndrome (CHS)

What Is Cannabinoid Hyperemesis Syndrome?

Cannabis hyperemesis syndrome, or CHS, is a rare condition some long-term cannabis users experience.

The word “hyperemesis” means severe vomiting, and many people with CHS also experience nausea and abdominal pain.

Cannabis (or marijuana) contains many active chemical compounds called cannabinoids. The two main compounds—tetrahydrocannabinol (THC) and cannabidiol (CBD)—bind with cannabinoid receptors in the brain, gut, and immune cells.

For many, these compounds don’t cause long-term issues, and their effects fade after a few hours. However, cases of CHS aren’t just side effects of using cannabis; CHS can cause intense pain and dehydration that requires visits to the emergency department.

Symptoms of Cannabinoid Hyperemesis Syndrome

The interactions of cannabis on the gastrointestinal and central nervous systems cause a whole suite of symptoms that may be mistaken for other conditions.

In addition, because CHS is relatively rare and may overlap with similar issues, it can be challenging to get an accurate diagnosis.

Common symptoms of CHS include:

• Intense nausea
• Several episodes of vomiting, up to five times per hour
• Severe abdominal pain
• Weight loss
• Dehydration and electrolyte issues in your blood
• Morning sickness
• Fear of throwing up
• Lack of appetite

CHS occurs in 3 distinct phases, which gives the condition the cyclical episodes many patients experience.

These 3 CHS phases include:

1. Phase 1—Prodromal phase: Adults who have used cannabis since their teenage years commonly experience the prodromal phase. Symptoms include abdominal pain or morning nausea, but patients often never actually vomit.
2. Phase 2—Hyperemetic phase: This phase typically lasts 24 to 48 hours and causes recurring, severe vomiting and nausea. Nausea in the hyperemetic phase may be so severe that patients find no relief even with antiemetic medications, which combat nausea caused by chemotherapy.
3. Phase 3—Recovery phase: The recovery phase begins when the patient stops using cannabis. While in the recovery phase, symptoms lessen over a few days or months and eventually disappear entirely.

CHS increases the risk of severe dehydration, which can be life-threatening. If you experience any of the following symptoms, call 911 or immediately go to the closest emergency room.

Symptoms of dehydration that require medical attention include:

• Dark or very little urine
• Delirium or confusion
• Dizziness
• Rapid breathing
• Fatigue or unexplained sleepiness
• Quickened heart rate
• Syncope (fainting)

Development of Cannabinoid Hyperemesis Syndrome

The exact cause of CHS isn’t known, but research indicates that chronic marijuana use since adolescence and certain genetics may increase the risk of developing the syndrome.

Other scientists theorize that overstimulation of the endocannabinoid system could cause CHS in some patients. The endocannabinoid system, or ECS, is a network of cannabinoid receptors in your body that respond to compounds like THC and CBD.

Typically, when compounds like THC and CBD bind with receptors in the brain, they prevent nausea and vomiting. However, when these compounds affect certain areas in the rest of the body, CHS symptoms can arise.

For example, when cannabinoids bind with receptors in the esophageal sphincter, a band of muscle that controls the flow of food from the throat to the stomach, the sphincter can malfunction. If this flap doesn’t work correctly, stomach acids can flow upward and cause nausea and vomiting.

Risk Factors for Developing CHS

Not all marijuana users develop CHS. However, research indicates that certain people are more likely to develop CHS than others.

Factors that put individuals at risk for CHS include:

• Genetics
• Chronic cannabis users who consume the substance at least once a week
• Cannabis users that consume doses higher than the recommended 40mg a day
• Long-term cannabis abuse since teenage years
• Dysregulation of certain cannabinoid receptors
• Toxic buildup due to the accumulation of cannabinoid components in the brain and fatty tissues

Long-Term Effects of Cannabinoid Hyperemesis Syndrome

Research has not yet indicated any long-term effects in CHS case reports once cannabis use has stopped. However, long-term outcomes related to recurrent vomiting raise some concerns for healthcare providers.

Long-term effects due to vomiting from CHS include:

• Dehydration
• Malnutrition
• Esophagitis (inflammation in the esophagus)
• Mallory-Weiss syndrome (tears in the esophagus)
• Tooth decay due to stomach acid
• Seizures
• Shock
• Kidney failure
• Muscle spasms or weakness
• Heart rhythm problems
• Brain swelling (cerebral edema)

How Common is Cannabinoid Hyperemesis Syndrome?

The prevalence of CHS appears relatively low among regular cannabis users, but research into the condition is still ongoing. Formerly identified and established as a known condition in 2004, there’s still much to learn about CHS.

According to a recent study, around 2.8 million people in the United States (approximately 1% of the population) use cannabis chronically and have symptoms consistent with CHS.

Cannabinoid Hyperemesis Syndrome Diagnosis and Treatment

As a relatively newer syndrome, healthcare professionals are still learning to diagnose and treat CHS. Many illnesses may overlap with the common symptoms of CHS, which poses quite a challenge for healthcare providers.

Diagnosis of Cannabinoid Hyperemesis Syndrome

CHS often gets misdiagnosed as cyclical vomiting syndrome or CVS, a rare disorder that usually starts in childhood and includes recurring bouts of vomiting without a known cause.

One way healthcare providers rule out CVS is by prescribing antiemetic medications like ondansetron; if the medication has no effect, the patient may have CHS.

To determine if you have CHS, your healthcare provider may ask the following questions to rule out other conditions:

• How often you use cannabis
• How long you have used cannabis
• When you vomit or feel nauseated
• If other factors or certain foods lead to vomiting
• Whether you have lost weight for no known reason
• If you take hot baths or showers to try to relieve symptoms

Your doctor may also order CT scans, MRIs, or a pregnancy test to rule out other causes of symptoms.

The current diagnostic criteria for CHS include:

• Regular cannabis use for over one year
• Severe nausea and vomiting
• Vomiting that recurs in a cyclic pattern over months
• Resolution of symptoms after stopping cannabis
• Compulsive hot baths/showers with symptom relief
• Abdominal pain

Treatment of Cannabinoid Hyperemesis Syndrome

Stopping the use of cannabis is the only known cure for CHS.

Although symptoms typically disappear a few days or weeks after stopping cannabis, certain treatments may help lessen the intensity of CHS symptoms.

Hot showers or baths are one of the easiest at-home remedies to help with CHS symptoms. Many people learn on their own that hot water helps curb nausea and may help regulate body temperature. However, this practice should be done in moderation, as hot water can worsen dehydration.

Common medical treatments for CHS include:

• Benzodiazepines
• Antihistamines like Benadryl®
• Topical capsaicin cream like Zostrix® for pain relief
• Antipsychotic medications like Zyprexa® (olanzapine) or Haldol® (haloperidol)
• Intravenous (IV) hydration for severe dehydration due to vomiting
• Pain relievers like ibuprofen (Advil®, Motrin®) or acetaminophen (Tylenol®)

Getting Treatment for Cannabinoid Hyperemesis Syndrome

If you or a loved one struggles with symptoms of CHS and is having a hard time stopping the use of cannabis, healthcare providers are ready and willing to help.

The Substance Abuse and Mental Health Services Administration (SAMHSA) offers an online treatment locator and a toll-free helpline ((800) 662-4357) to help you find a treatment center to help you stop using cannabis.