It’s not entirely clear how cannabis hyperemesis syndrome occurs though there are several theories. One is that since cannabinoids have long-half lives and are lipid soluble, they accumulate in the brain and over time cause symptoms, particularly in young people who may have genetic variations in enzymes which lead to further accumulation. Another theory is that there is a thermoregulatory and autonomic imbalance in the limbic system caused by chronic use. Other suggestions are that with long-term consumption cannabis becomes a receptor antagonist, or that they become down-regulated or de-sensitised over time. This reverses the antiemetic effect of cannabis. It seems that chronic over-stimulation of receptors leads to dysregulation of the body’s control of nausea and vomiting, leading to CHS.

Owen Hibberd . What you need to know about Cannabinoid Hyperemesis Syndrome, Don’t Forget the Bubbles, 2022. Available at: https://doi.org/10.31440/DFTB.48627

I am so glad I never inhaled.