A strange illness is making weed users vomit and want hot showers

I was recently contacted by a paramedic who reads this column. He asked me if I’d heard about an illness that makes heavy consumers of cannabis violently vomit and develop an insatiable desire for a hot shower. I had not.

He’s seen a few cannabis-using patients with these symptoms in the past year. ​“They present to us wrenching and relentlessly being sick,” he told THE FACE. ​“Also with abdominal pain.” He remembers one patient specifically. ​“It was a young guy, he was sick and hysterical with abdominal pain. As soon as he got to the hospital, he made a beeline for the showers and had a hot shower because it [temporarily] relieved his symptoms.”

These symptoms are known as cannabinoid hyperemesis syndrome (CHS). According to the NHS, it’s ​“a rare condition caused by a regular (daily) and long-term use of marijuana. […] The syndrome is characterised by repeated and severe bouts of vomiting.” And, in line with the report from the aforementioned paramedic, the NHS also mentions that ​“many people will take a lot of hot showers during the day to ease their nausea”.

The illness has also led to the development of a terrifying new term: ​“scromiting”, used to describe someone who is simultaneously screaming and vomiting. According to Newport Academy, who offer addiction services in the US, the phenomenon has been linked to intaking high levels of THC (a main ingredient in cannabis that’s largely responsible for the high) which some researchers believe can overstimulate receptors in the gut.

CHS is a rare condition. It’s estimated that between 1.5 and 2 million people in the UK use weed recreationally ​“at least” once a month and most have never heard of it. But it’s an illness that’s perplexing doctors both in the UK and abroad. As illnesses go, it’s a ​“relatively newly-defined condition”, although there have been isolated cases reported as far back as the year 2001 in Australia. Researchers don’t know how it’s caused or why it only affects some people, and there’s no test for it. But, according to the expert I spoke to, CHS could be on the rise in the UK.

Dr Chris Humphries has researched this topic for the Royal College of Emergency Medicine. Can he shine any light on how common CHS is in the UK? ​“Unfortunately, not at this time. Clinical coding data for Emergency Medicine is not specific enough to identify patients presenting with CHS, and the rates of CHS diagnosed during hospital admissions are not published.”

Crucially, though, ​“anecdotally, numbers are rising,” Dr Humphries says. ​“But it is impossible to know if this is due to better recognition by clinicians, or increasing rates.”

While we don’t have specific data on CHS in the UK, in North America and Canada, researchers are reporting a sharp increase in this mysterious illness. ​“Though still rare among cannabis users, the prevalence of CHS has soared in the past decade,” journalist Corryn Wetzel recently wrote in New Scientist.

If someone turns up at a hospital in the midst of a bout of CHS, what can doctors do about it? ​“CHS is a vomiting disorder,” Dr Humphries explains, ​“so the treatment of an episode is aimed at stopping vomiting, and fixing any of the complications of vomiting [like dehydration, electrolyte disorder or injury].”

Routine anti-sickness medicines are not as effective at stopping vomiting from CHS, but apparently an anti-psychotic medicine called haloperidol can sometimes help in low doses. Long-term, though, the only treatment that appears to be effective is to permanently stop using cannabis.

As for the hot showers, research from the Royal College of Emergency Medicine, published last year, found that 92 per cent of the suspected CHS patients reported ​“relief of symptoms with hot showers or baths”. Meanwhile, the New Scientist article reports that ​“experts think [a] warming sensation, similar to the effect of taking a hot shower, activates a receptor in the stomach that can calm nausea and vomiting”.

One thing that makes this a particularly curious illness is the fact it contradicts facts we already know about smoking weed. Cannabis is sometimes prescribed to treat nausea and vomiting, after all, and for some people it’s very effective, often used to combat nausea caused by chemotherapy. But for a small minority, it seems to be causing the very symptoms it’s supposed to treat.

“Ideas about why they can cause vomiting for some people are still theoretical,” Dr Humphries tells THE FACE. ​“It might be that, when stimulated long-term, the body’s natural cannabinoid receptors can become dysfunctional, or it might be genetic. It is difficult to point to a cause at the moment.”

By all accounts, CHS is extremely unpleasant for anyone unlucky enough to have a run in with it. But is it that serious? ​“There have been case reports of deaths occurring as a result of CHS,” Dr Humphries says. ​“There have also been cases of burns from people self-treating with hot baths. But without knowing the true rates, it is impossible to quantify the risks accurately.” Injuries that result from extreme, prolonged levels of vomiting come indirectly – severe electrolyte derangement (which can cause seizures, or heart problems), kidney failure from dehydration, or a tearing of the oesophagus, for instance – rather than from the act of vomming itself.

If you’re a cannabis user who has never had these symptoms, don’t worry too much about developing them – this is a rare illness, after all. But people who use weed (whether that be medical or recreational) should be aware that CHS exists. Not sure about you, but I’ll be having nightmares about scromiting.

If you think you might need medical attention, ring NHS 111. If you have severe pain, or if you have had vomiting for a day or more, seek medical attention by going to A&E or calling 999