The story
Ten years, in nine chapters.
How it started, what every test said, what it cost, and the morning it finally got a name. Read the story →
Cannabinoid Hyperemesis Syndrome
What I wish I'd known ten years ago.
If you are standing in a hot shower at 3 a.m. wondering what is wrong with you, this was written for you, by someone who spent a decade there.
This site is written by a person who had CHS, not a doctor. Here is exactly how every number on it was checked, and what is still unknown.
I didn't believe it either. So I tested it.
I was 23. I woke up nauseous and figured I had a stomach bug. The bathroom I shared had a tub I never used because it was gross. That morning it was the only thing I wanted. I sat in it for two hours and fell asleep in the water. My heart was racing. I had no idea what was happening to me.
I got better. I stayed clean for about a year and got in the best shape of my life. Then I started working in a restaurant, got around people who smoked, and told myself I could handle a little at night.
It came back. It has come back six times now, and it has been worse every time.
That is the part almost nobody tells you. Most people do not believe this diagnosis. They test it. I tested it six times.
Where are you right now?
Pick the one that sounds like tonight.
- Sick right nowMid episode, can't stop throwing up. Start here.→
- I don't know if this is even itSix questions. Dangerous causes first, then an honest answer.→
- Not sure it's the weedPart of you doesn't buy it. Read the case, weaknesses and all.→
- Someone told me this is what I haveHere is what it actually is.→
- I quit and I'm still not rightThe timeline is longer than anyone tells you.→
- I went back and I feel ashamedAlmost everyone does. It isn't the end.→
- Someone I love is doing thisThere is a way to help.→
What this actually is
Cannabis calms nausea in small doses. That is why it is given to chemo patients. Use enough of it for long enough and it flips. The same plant that settled your stomach starts wrecking it, in cycles, and it will not stop on its own.
The cruel part is the timing. It usually hits the next morning, not while you are high. And more cannabis really does calm it for a few hours. So the thing causing it looks exactly like the thing fixing it. That is how it hides for years.
Throwing up once from too big a dab is an overdose, not this. This is the cycle that keeps coming back.
It is real and it has a name. It has been in medical journals since 2004. US medicine gave it a diagnostic code, R11.16, in October 2025. Most doctors still have never said it out loud, and in a 2026 national survey only 11.5% of people whose symptoms fit CHS had ever been told what it was. The evidence page has the full case, including the parts researchers still argue about, and the history page covers where it came from.
How it moves
Cannabis did not become a different plant. It became a much larger dose of the same one, from around 1 to 2% THC in 1970s flower to 70 to 85% in concentrates, and this shows up at the top of that ladder. The evidence page argues both sides of that.
Phase 1
The warning
Morning nausea. A tight stomach. Heartburn, loose stools, hot and cold sweats, anxiety. You feel sick but you rarely throw up. Most people smoke more here, because it helps, and that is what speeds the whole thing up.
It is the easiest point to stop and the hardest one to take seriously. If you are a daily user waking up with that cluster, this is the early warning.
Phase 2
The episode
Vomiting you cannot stop. Retching every few minutes. Pain bad enough that people scream through it. Hot showers give more relief than anything else anyone has found, though as you'll see below, that response by itself does not prove which condition you have.
Here is what nobody writes down. It is not only your stomach. It is dread. It feels like you are slowly dying and like nothing will ever make it stop. You lose track of what day it is. You are only trying to get through the next minute.
Phase 3
After you stop
Starts the day you quit for good. The vomiting usually eases in the first week or two. Your nervous system takes longer, and longer than most pages like this admit. Going back, including edibles, vapes, and in rare reports even CBD, can restart it.
What actually helps
Ranked by how consistently patients and studies report it working. None of this is medical advice.
First, make sure it is actually this.
Vomiting and belly pain can be a lot of things. Appendicitis does not skip you because you smoke, and people who really do have CHS can get something else on top of it. Go to an emergency room now if you have any of these: blood in your vomit or stool, vomit that looks like coffee grounds, severe or one-sided pain, high fever, chest pain, a racing or pounding heart, confusion, a seizure, no urine for 12 hours or more, or you are or might be pregnant.
If your symptoms change character, go back and get checked again. Having had this for months tells you nothing about tonight. The fuller list a clinician is asked to rule out lives on the ER card page. Everything below is for after those are ruled out.
- 1
Hot water
Read this one
91 to 92% of patients in clinical studies get relief from it. More than anything else. Nobody has proven why.
The hot shower is not a test, and it never was
This site is named after the thing that gave a lot of us away, and that part is fair, hot water relief really is the most reported thing in this condition. But it does not confirm CHS, and it never should have been treated like it does.
In the largest cyclic vomiting syndrome survey ever run, 67% of everyone with cyclic vomiting used hot showers or baths for relief, cannabis user or not. In a cohort of 111 cyclic vomiting patients, 73% used hot water bathing and got real relief, and only about 17% of that group used cannabis regularly. In a 2026 national survey of thousands of adults, only 47.2% of people whose symptoms fit CHS said a hot bath or shower helped them at all.
So a hot shower working on you raises the odds this is CHS. It does not prove it, and a hot shower not working does not clear you either.
Go as hot as feels soothing, not as hot as you can stand. Stinging, pain, or your skin going numb means it is too hot, not that it is working. There is no established target temperature and this page will not print one. It used to say 109 to 112 degrees Fahrenheit. That number never had a real source behind it, and printing it was a mistake. The only published hospital pathway that names a limit, the Johns Hopkins All Children's Hospital CHS pathway, caps it at 100 F. Never go above 120 F. The US Consumer Product Safety Commission's own scald data show a third degree burn in well under a minute past that point, and people with CHS have burned themselves badly enough to need intensive care doing exactly this.
Staying safe in there
People pass out in the shower. You are dehydrated, you have been vomiting for hours, and you are sitting in heat. I fell asleep in a bathtub on my first morning of this and had no idea that was dangerous. Sit down. Leave the door unlocked. Tell someone you are getting in. Keep your phone where you can reach it. If you feel faint or your heart is pounding, get out and cool off.
91 to 92% relief in clinical studiesThe heat and cold loop
You will get overheated in the hot water, then want something ice cold, then want the hot water again. That cycle is normal and it costs you fluid, because you are sweating out water you cannot keep down. Cool off between rounds with a cold cloth or a fan rather than by staying in longer.
- 2
Capsaicin cream
Read this one
Over the counter, 0.025 to 0.1 percent. A thin layer on your stomach. Wash your hands right after. Wait for the burn, then the relief.
Use less than you think, and pick one heat source at a time. A thin smear, not a handful. And do not put it on and then get in hot water. I did that and it spread through the water and burned everywhere, including places you do not want burned. Capsaicin works by switching on the same heat receptor a hot shower does, so using both together is how people end up with real burns.
Used in ERs since the mid-2010s - 3
Fluids, in whatever form you can keep down
Read this one
Electrolyte drinks, Pedialyte, salted broth. Cheap and simple beats fancy. One sip at a time, do not chug.
If you cannot keep down even a sip, ice chips. That is what got me through the worst of it when nothing else stayed in. Dehydration is what turns a bad night into a hospital stay, and in this condition it can damage your kidneys.
Prevention, not rescue - 4
Ginger. Candies, tea, capsules
Read this one
Will not stop a full episode. Helps with mild early nausea and in the first days after quitting.
Best for early / mild days - 5
If you cannot afford an emergency room
Read this one
I have had this six times and I have never once been to an ER, because of what it costs. What kept me alive was an IV hydration clinic. My brother drove me to one when I had gone eleven days without food or sleep and had started hallucinating.
It worked in real time. Fluids in the arm do what sips of Gatorade cannot when your stomach is rejecting everything. They also put an anti-nausea drug straight into the line, which did more than anything I had swallowed. That is not a coincidence: pills do not work when you cannot keep them down.
Two honest things about this.
An IV clinic rehydrates you. It does not rule out anything. It cannot tell you whether this is a bowel obstruction or appendicitis. If any of the red flags above are true, an IV clinic is the wrong door. Go to the hospital, cost and all.
Prices vary and mine were not typical. The nurses gave me a large discount because they were worried about me, so my number is not a number anyone should plan around. Call and ask before you go. Ask whether they can add an anti-nausea medication to the bag.
Rehydrates, does not diagnoseWhy there is no price on this page
Nobody has published what CHS rehydration actually costs at an IV clinic, and one person's discounted bill is not data. We would rather print nothing than print a number that gets quoted back as fact. If you have been to one, tell us what it cost and we will publish a real range.
- 6
The emergency room, and how to be heard
Read this one
If you have gone 24 hours without keeping fluids down, go. You do not have to diagnose yourself and you should not demand specific drugs. Try this: "I'm a heavy daily cannabis user, hot showers relieve this, and I think it may be Cannabinoid Hyperemesis Syndrome. Please rule out other causes, and can we consider the treatments the research supports?"
Worth asking for by name: "can you check my potassium and do an ECG?" Days of vomiting strip out potassium, low potassium stretches the heart's QT interval, and several of the drugs used here stretch it too. Hospital protocols check both first. Asking makes their job easier.
Standard anti-nausea drugs often underperform here. Haloperidol beat Zofran in a head-to-head trial. Guidelines say opioids should not be first line and can make it worse. Our printable ER card says all of this for you, in a way that helps the doctor instead of arguing with them.
Ask, don't demand - 7
Ask about a long term medication, if you keep cycling
Read this one
Amitriptyline, named in a 2024 gastroenterology guideline update, usually 75 to 100 mg at bedtime, started low. Most of the evidence comes from cyclic vomiting syndrome, a related condition, not from trials in CHS. A real question for a doctor, not something to start on your own.
Ask a doctor, borrowed evidence
If you are mid-episode right now
A checklist for the next hour. Tap what you have done.
0 of 9 done
If tonight is worse than nausea
People describe this phase as dread, not just sickness. Some describe wanting it to be over in a way that frightens them. That is a known part of how bad this gets, and it is a reason to call somebody, not a reason to be ashamed. These are free, they run all day and all night, and none of them will ask what you smoked.
- 988, call or text. The US Suicide and Crisis Lifeline, for any kind of crisis, not only suicide.
- Text HOME to 741741. Crisis Text Line, if talking out loud is not possible.
- 1-800-222-1222. Poison Control, if you have taken too much of anything, including something you took to make this stop.
- 1-800-662-4357. SAMHSA national helpline, free and confidential, for treatment referrals.
You are not doing this alone
Somebody is watching this happen to you.
They usually have no idea what to say. There is a page for them, written for the person in the room rather than the person on the floor.
Someone is watching this happen to you
They usually have no idea what to say. Believe them, out loud. Half the cruelty of this is that it looks like something the person is doing to themselves, and everyone around them says so.
If they cannot keep fluids down for a day, or you see blood, confusion, or no urine, that is the emergency room.
The families page is written for you.
After you stop
The clock nobody starts for you.
Days to a few weeks for most people. One to three months for a meaningful group. And a tail beyond that which research has never measured.
After you stop
Vomiting usually eases in the first week or two. For the patients with real follow-up data the figure was 1 to 3 months. Community reports run from days to years past that, and nobody has run the study that explains why.
Quitting brings its own nausea, starting 24 to 48 hours after your last use and peaking around day 2 to 6. It commonly runs two to three weeks or longer, and sleep is usually the last thing to settle. All of that is withdrawal, not the CHS coming back. You cannot get this from quitting, only from using.
“
If you've ever found yourself standing under a scorching hot shower at 3 a.m. because it was the only thing keeping you from vomiting again ... you are not alone.from a CHS patient community
The trap
The part that catches almost everyone.
Not disbelief. Believing it, and thinking there is a version of using that gets around it.
About "just one hit"
Once your body has learned this, it doesn't forget.
A 2022 survey of 205 people with CHS found 79% returned to cannabis at some point. If that is you, you are the rule, not the failure.
Here is how it went for me every time. A little at night. A few weeks later, a gram a day. A couple of months later, an eighth a day. By month three I was sick again. Every night turns into every morning, then morning, lunch and dinner, and then it is your whole life again. There is no safe test dose.
The evidence
For the part of you that still doesn't believe.
Twenty years of research, the whole argument, and the honest parts too, including where doctors still disagree. Built to be read by a skeptic.
See the whole case →The last time
The only version of this that ends is the one where you stop.
Not quickly and not easily. Full cessation is still the only thing in the research that reliably ends it.