Ask Dr. Leigh: Why does cannabis make me nauseous?


Using cannabis can have a big impact on your physical and mental health—for better, and sometimes for worse. That’s why it’s important to consult a healthcare provider before experimenting.

Here at GreenState, cannabis clinician Dr. Leigh Vinocur is here to answer your questions on healthy living with cannabis.

Editor’s Note: The answer to this question is meant to supplement, not replace, advice, diagnoses, and treatment from a healthcare provider.  Always consult a medical professional when using cannabis for medicinal purposes, and do not disregard the advice of your healthcare provider because of anything you may read in this article. 

Q: Why does cannabis make me nauseous?

A: If consuming cannabis makes you feel like vomiting, you may have something called Cannabinoid Hyperemesis Syndrome. Cannabinoid Hyperemesis Syndrome (CHS) is a condition caused by chronic daily cannabis use, and is characterized by symptoms of cyclical nausea, vomiting, and abdominal pain with cramping.  Oddly, the symptoms are relieved by hot showers or baths, which almost become compulsive with those who have the syndrome. It was first described in 2004, attributing it to chronic cannabis use as opposed to previously being believed it was psychogenic vomiting, meaning having a psychological origin.  It was a somewhat rare condition, but, with the increase in cases more recently, it is believed to be due to the more potent and higher levels of THC we are seeing in the legal cannabis industry today, compared to the illicit industry from years ago.

Paradoxically, cannabis can suppress nausea and vomiting centers in the brain and it is used for chemotherapy-induced nausea and vomiting (CINV).  While the reasons for why cannabis can cause increased nausea and vomiting in CHS are still not yet fully understood, it is believed that THC causes overstimulation of the endocannabinoid receptors in the gut.

It is believed to be underdiagnosed and underrecognized in the emergency room, sometimes leading to long and expensive medical work ups and hospitalization, especially if the doctors fail to take a history or ask about cannabis use. The dangers with continuous vomiting are severe dehydration and electrolyte loss, which can be very serious and lead to heart problems and dangerous irregular heart rhythms if not addressed and treated with intravenous fluids.

There are 3 stages we see in this condition. The first called prodromal, which can go on for months or years. It is characterized by morning nausea and abdominal pain but not a lot of vomiting. The second stage is when the vomiting occurs with some patients experiencing over 20 bouts a day. This is called the hyperemetic stage and it leads to weight loss and severe dehydration and electrolyte loss. This is the stage where people start to compulsively bath and shower, because of the short-term relief. The recovery stage occurs within a couple days of stopping cannabis use and is the best long term treatment option, because symptoms usually return once patients start consuming cannabis again.

Aside from requiring extensive fluid and electrolyte replacement, other therapies have been tried such as, antinausea medications. Because hot showers help some have tried using warming creams such as, capsaicin cream which is the chemical found in hot peppers. Also, acid reducing stomach medication is given too. However, nothing is as effective as cessation of cannabis use.

While we still don’t understand why some people develop this disease and others don’t a recent study led by renowned cannabis physician and researcher Dr. Ethan Russo, looked at the genetics in CHS patients. Interestingly, they found that these patients had common associated mutations in their genes affecting cannabis metabolism, related to their neurotransmitters, their endocannabinoid system and their liver metabolizing enzymes called the cytochrome P450 system. This groundbreaking research will pave the way for better understanding the pathophysiology of this disease and will then help create future treatments.

Got cannabis questions? Ask Doctor Leigh. Send your questions to GreenState’s Editor at and keep an eye out for new answers from Dr. Leigh Vinocur every month.

Dr. Leigh Vinocur is a board-certified emergency physician who also has a cannabis consulting practice for patients and industry. She is a member of the Society of Cannabis Clinicians and a graduate of the inaugural class, with the first Master of Science in the country in Medical Cannabis Science and Therapeutics from the University of Maryland School of Pharmacy.

The response to this question was not written or edited by Hearst. The authors are solely responsible for the content.

Leigh Vinocur, MD