For many people, marijuana is known for its relaxing effects and for easing pain or anxiety. But doctors are warning about a little-known condition that can have the opposite effect.
Some heavy users are developing severe, repeated episodes of nausea and vomiting that can become so intense they end up in emergency rooms again and again. This condition is called cannabinoid hyperemesis syndrome, or CHS, and it is becoming more common as cannabis use increases.
At first, many doctors did not believe the illness was real. When early reports appeared in medical journals about patients who could not stop vomiting after long-term marijuana use, some physicians were skeptical. Over time, however, emergency departments began seeing more and more cases.
In places where cannabis became legal earlier, such as Colorado in the United States, doctors noticed a sharp rise in patients with the same pattern of symptoms.
CHS usually occurs in people who use marijuana heavily, often every day for a year or more. The main symptoms are severe nausea, repeated vomiting, stomach pain, and dry heaving that can last for hours.
Many patients feel worst in the morning. Some episodes become so serious that patients become dangerously dehydrated or develop kidney problems. In rare cases, repeated vomiting can even tear the esophagus, the tube that carries food from the mouth to the stomach.
Doctors still do not fully understand why marijuana triggers this reaction in some people but not others. Cannabis contains many chemicals that interact with the brain and digestive system.
While small amounts can reduce nausea, long-term heavy use may disrupt the body’s normal control of the stomach and brain signals, eventually causing the opposite effect. Modern cannabis products are also much stronger than those available decades ago, which may contribute to the problem.
The rise of CHS seems closely linked to the growing availability and popularity of cannabis. Studies analyzing millions of emergency department visits across the United States show that cases of CHS have increased dramatically over the past decade.
Young adults appear to be especially affected, possibly because they are more likely to use cannabis frequently and in higher doses.
Diagnosing CHS can be difficult because its symptoms look similar to those of other stomach illnesses. Some patients are reluctant to tell doctors about their cannabis use, which can delay proper diagnosis.
For years there was not even a specific medical code for the condition, making it harder to track how common it was. A formal diagnostic code was only introduced recently.
Treating CHS can also be challenging. Standard anti-nausea medications often do not work well for these patients.
Doctors usually provide intravenous fluids to treat dehydration and may use older medications or certain drugs normally used for mental health conditions that appear to calm the symptoms more effectively. Some patients report temporary relief from taking hot showers or baths, although scientific evidence for this is limited.
The most important treatment, however, is stopping cannabis use completely. Many patients improve once they quit, but some return to using marijuana and experience the same severe symptoms again. This cycle highlights how difficult it can be for some individuals to stop, especially if they have become dependent on the drug.
In reviewing the evidence, the growing number of CHS cases raises important public health questions. Legalization and increased potency have made cannabis more accessible than ever, but awareness of potential risks has not always kept pace.
While marijuana can have medical benefits for some people, this research shows that heavy long-term use may carry serious consequences. The condition also illustrates how substances that relieve symptoms in the short term can cause harm when used excessively over time.
More research is needed to understand why only certain people develop CHS and how to prevent it. In the meantime, doctors emphasize the importance of honest conversations between patients and healthcare providers about cannabis use. Recognizing the symptoms early can prevent repeated hospital visits and serious complications.
Overall, CHS serves as a reminder that no drug is completely harmless and that the body can react in unexpected ways. As cannabis becomes more widely used around the world, public education and careful monitoring will be essential to protect people’s health.
If you care about smoking, please read studies about smoking may increase heart disease risk by 200% and e-cigarette smoke may cause lung cancer and bladder disease.
For more health information, please see recent studies about the cause of weight gain after smoking cessation, and results showing smoking may cause white scars on the brain.
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