Cannabis hyperemesis syndrome
Regular and long-term use of cannabis (marijuana) and synthetic cannabis can cause ongoing feelings of wanting to throw up (nausea), throwing up (vomiting) often, and tummy (stomach) pains. This condition is called cannabis hyperemesis syndrome (CHS). It can be a serious condition. The only treatment is to completely stop using cannabis.
Causes of cannabis hyperemesis syndrome
The exact causes of CHS are not known. In some people, the long-term use of cannabis affects receptors in the gut. This can cause you to feel sick (nausea) and throw up (vomit). Receptors are specialised groups of cells that detect a stimulus and send signals to your brain.
CHS can happen if you have used cannabis at least weekly for several years. It is more common if you have used cannabis since you were a rangatahi. It can happen with any type of cannabis use — smoking, inhaling or eating.
Symptoms of cannabis hyperemesis syndrome
To start with, you may have:
- nausea, especially in the morning
- stomach pains
- a fear of vomiting.
This stage can last for weeks, months or years.
Later you may develop:
- more constant nausea
- stomach pain that can be severe
- bouts of frequent vomiting that last 1 to 2 days
- dehydration
- a loss of appetite and weight loss.
Severe symptoms may only last for 1 to 2 days. But they will come back if you use cannabis again.
Diagnosing cannabis hyperemesis syndrome
Repeated vomiting has many possible causes.
If you have symptoms of CHS, you will need to tell your healthcare provider about your cannabis use to help them decide if this is the cause. They will ask you about your symptoms and examine you.
You may have blood tests, a urine test or imaging tests such as an ultrasound or CT scan. These are to rule out other causes of your symptoms.
Treating cannabis hyperemesis syndrome
If you have severe vomiting, you may need short-term treatment such as:
- fluids given into a vein (IV) to treat dehydration
- anti-nausea medication
- pain medication.
Many people find hot water temporarily relieves their symptoms, so they may spend hours in the shower or bath.
The long-term treatment is to completely stop using cannabis. Just reducing your use will not cure the problem.
When you stop using cannabis, you will begin to feel better after a few days. But it can take weeks before all your symptoms go away. Your symptoms are likely to come back if you use cannabis again.
Getting help with cannabis hyperemesis syndrome
If you have been able to use cannabis for years without problems, it can be hard to accept that cannabis is the cause of your symptoms.
Completely stopping using cannabis can be difficult.
To get help, see your usual healthcare provider or try to find community support.