Hyperemesis Cannabis Syndrome: What You Need to Know

Cannabinoid Hyperemesis Syndrome (CHS) is a condition that affects some people who use cannabis, especially over a long period. First described in 2004, it is a lesser-known condition that causes severe nausea, vomiting and abdominal pain, often leading people to seek medical help. For many cannabis users, the symptoms can be confusing and alarming because cannabis is often thought to help with nausea.

That paradox is why CHS is often missed: the cannabis a person may be using for nausea is the cause, and only stopping it brings lasting relief.

What is CHS?

Cannabinoid Hyperemesis Syndrome (CHS) is a condition that affects some people who use cannabis for a long time. It causes severe symptoms like nausea, vomiting, and stomach pain. While cannabis is often used to relieve nausea, in the case of CHS, it has the opposite effect, making symptoms worse.

The exact cause of CHS isn’t fully understood, but it is believed to be the body’s reaction to long-term cannabis use. Many people with CHS find relief through hot showers or baths, which provide temporary comfort. Knowing what cannabinoid hyperemesis syndrome is can help people seek medical care early.

Symptoms of CHS

Cannabinoid Hyperemesis Syndrome (CHS) has several symptoms that can be quite severe and distressing. The most common cannabinoid hyperemesis syndrome symptoms include:

Severe Nausea and Vomiting: Frequent, intense bouts of nausea and vomiting are the main symptoms of CHS. These episodes can last for days or weeks, leading to dehydration, weight loss, and fatigue.
Abdominal Pain: Many experience intense stomach pain or cramping, which can be mild or severe, making it hard to eat or drink.
Relief with Hot Showers: A unique sign of CHS is the temporary relief found through hot showers or baths. This helps reduce nausea but only offers short-term comfort.
Avoidance of Food and Drink: Many with CHS avoid eating and drinking, which can worsen dehydration and malnutrition. Social activities may also be avoided due to symptoms.

Phases of CHS

CHS typically progresses through three phases:

Prodromal Phase: Early stage with mild symptoms like morning nausea or discomfort. It comes before the episodes of severe vomiting begin.
Hyperemetic Phase: The most intense phase, marked by severe nausea, vomiting, and stomach pain. Frequent hot showers or baths may provide temporary relief. Symptoms can be so severe that hospitalization is needed. A 2011 review found this phase usually ends within 48 hours.
Recovery Phase: Begins when cannabis use stops. Symptoms gradually improve, and health recovers. Stopping cannabis use is what keeps symptoms from returning for most people.

By recognizing these symptoms and understanding the different phases, people who use cannabis can spot CHS sooner and get the medical care they need to recover.

Causes and Risk Factors

In a 2017 review of 183 articles, every reported case of cannabinoid hyperemesis syndrome (CHS) involved regular cannabis use. CHS is linked to heavy or long-term cannabis use, and while the exact cause is still being studied, there are several potential mechanisms and risk factors that may lead to this condition. Users who recognize the signs early can seek treatment sooner and avoid further complications.

What Causes CHS?

Cannabinoid Hyperemesis Syndrome is thought to occur due to the overstimulation of cannabinoid receptors in the brain and digestive system from heavy or long-term cannabis use. One proposed explanation, rated as very low quality evidence in a 2017 systematic review, is that heavy use desensitizes these receptors; the exact mechanism is still unknown. Although cannabis typically reduces nausea, in CHS, it has the opposite effect, causing symptoms to worsen.

Potential Mechanisms Behind CHS

The exact cause of CHS isn’t fully understood, but researchers believe it involves the body’s natural cannabinoid system. Cannabis interacts with receptors in the brain and digestive tract, and in cases of cannabis hyperemesis syndrome, these receptors may become overstimulated. This overstimulation can disrupt normal digestive functions, causing symptoms like nausea, vomiting, and stomach pain. Additionally, the urge for hot showers to relieve symptoms may relate to how the body manages temperature and discomfort.

Differences Between CHS and Cyclic Vomiting Syndrome (CVS)

While both CHS and Cyclic Vomiting Syndrome (CVS) cause severe vomiting, their causes differ. CHS is directly linked to long-term cannabis use, while CVS is not related to cannabis. People with CVS may have other triggers like migraines or stress, but their symptoms do not improve by stopping cannabis use, unlike those with CHS.

Risk Factors for CHS

Certain factors increase the risk of developing CHS. These include:

Long-Term Cannabis Use: People who have used cannabis regularly for a long time are more likely to develop CHS.
Frequent Cannabis Use: The more often a person uses cannabis, the higher their risk of developing cannabinoid hyperemesis syndrome.
Age and Sex: A 2017 review found most cases involved men, but a 2026 CDC analysis of 199,565 emergency visits found a higher share among people aged 15 to 24 and among females.
Other Factors: Researchers do not yet know why only some frequent users develop cannabinoid hyperemesis syndrome symptoms; a 2017 review found the cause unclear.

The common thread in reported cases is frequent, long-term use, so that is the pattern to watch for. Spotting CHS early can help prevent serious problems such as dehydration and improve the quality of life for those affected.

Diagnosis of CHS

Diagnosing Cannabinoid Hyperemesis Syndrome (CHS) can be challenging because its symptoms, like severe nausea and vomiting, are common in many conditions. However, certain patterns can help doctors identify CHS more accurately. Here’s how CHS is diagnosed and how it differs from other conditions.

How CHS is Diagnosed?

Doctors use the following steps to diagnose CHS:

Medical History: The doctor will ask about cannabis use, including the frequency and duration of use. Regular use is a key sign: a 2017 review found regular cannabis use in every case.
Symptom Assessment: Doctors check for symptoms like repeated nausea and vomiting that improve with hot showers or stopping cannabis.
Physical Examination: A thorough exam helps rule out other potential health issues.
Exclusion of Other Causes: Tests such as blood work or imaging may be done to rule out gastrointestinal disorders, infections, or other conditions that mimic CHS symptoms.
Observation of Symptom Relief: If symptoms improve after stopping cannabis use, it supports the diagnosis of CHS.

Differentiating CHS from Other Conditions

Doctors also have to tell cannabis hyperemesis syndrome apart from other causes of repeated vomiting:

Cyclic Vomiting Syndrome (CVS): CVS is not linked to cannabis use and can be triggered by stress, infections, or foods, unlike CHS.
Gastrointestinal Disorders: Disorders like gastritis or acid reflux can cause nausea, but their symptoms don’t typically change with cannabis use.
Pregnancy-Related Nausea: For women, pregnancy should be ruled out as a cause of nausea and vomiting, as these symptoms are unrelated to cannabis use.

If you suspect you have CHS, see your primary care doctor or an urgent care clinic, and say how often you use cannabis so they can rule out other causes.

Treatment and Management

Treating Cannabinoid Hyperemesis Syndrome (CHS) focuses on relieving symptoms and preventing their return. Since CHS is a condition directly linked to cannabis use, stopping cannabis is the most effective approach. Here’s how to manage CHS in the short and long term.

Immediate Management of CHS

If you have symptoms of cannabis hyperemesis syndrome, such as severe nausea and vomiting, try these steps:

Stop Using Cannabis: The first step is to stop all cannabis use, which helps reduce symptoms and prevents them from worsening.
Stay Hydrated: Drink fluids to prevent dehydration from frequent vomiting. Electrolyte drinks help replace the fluids and salts lost through vomiting.
Take Hot Showers or Baths: These can provide temporary relief from symptoms, although they do not cure CHS.
Seek Medical Help: If vomiting is severe or you cannot keep fluids down, get urgent care; doctors may use IV fluids and other medicines.

Long-term Management and Prevention

To prevent CHS from returning, consider these strategies:

Avoid Cannabis Completely: Stopping cannabis entirely is the step that ends CHS for most people: in the 2017 review, symptoms resolved after stopping in 96.8% of cases.
Regular Check-ups: See your doctor regularly to monitor recovery and address any underlying health issues.
Educate Yourself: Learning about CHS can help you recognize symptoms early and make informed choices.
Lifestyle Changes: Manage stress, maintain a balanced diet, and stay hydrated to support overall health and avoid triggers.

If you suspect CHS, a doctor who knows your full history is the right first stop; you can still contact us with questions about medical cannabis.

The Impact of CHS

Cannabis Hyperemesis Syndrome (CHS) can greatly disrupt a person’s life. The constant nausea, vomiting, and abdominal pain make daily activities like work, socializing, and maintaining a healthy lifestyle very challenging. Those effects reach well beyond the stomach.

Impact on Quality of Life

CHS is a condition that lowers the quality of life. Frequent symptoms like nausea and vomiting cause dehydration, fatigue, and weight loss, making it hard to perform everyday tasks or enjoy social activities. This can lead to frustration and isolation.

Physical, Emotional, and Social Effects of CHS

Physical: Ongoing stomach pain, dehydration, and tiredness can lead to further health issues.
Emotional: Constant symptoms can cause anxiety, stress, and even depression.
Social: Avoiding activities and social interactions due to symptoms can result in loneliness and withdrawal.

Challenges Faced by Individuals with CHS

People with CHS often struggle with:

Diagnosis: CHS is often missed; a specific diagnosis code only took effect in October 2025, CDC reports.
Quitting Cannabis: Stopping cannabis use, which a 2017 review says appears to be the best treatment, can be very difficult.
Finding Relief: Temporary measures like hot showers help, but only stopping cannabis brings long-term relief.

Public Health Considerations

Emergency visits for CHS now have their own diagnosis code, CDC reports, so CHS is easier to track than before. Better education can help people recognize symptoms early and seek treatment, improving outcomes and reducing healthcare burdens. The first step is the same for everyone: tell a doctor how often you use cannabis.

Conclusion

Cannabis Hyperemesis Syndrome (CHS) can seriously impact a person’s life, causing ongoing nausea, vomiting, and abdominal pain that disrupt daily activities, work, and social interactions. These symptoms lower the quality of life, leading to physical exhaustion, emotional stress, and social isolation.

Repeated vomiting in someone who uses cannabis often is worth raising with a doctor, even if cannabis seemed to help at first. Early recognition and proper treatment can help those affected manage their symptoms and improve their well-being. If you suspect you have CHS, seek guidance from a healthcare professional for the best care and support.

What Is Cannabinoid Hyperemesis Syndrome?

What is CHS?