I am an Internist and teach at a well known medical school. I have actually cared for quite a few folks with Cannabanoid Hyperemesis Syndrome CHS). I have never had anyone try to scream while vomiting. The article mentioned is biased, misleading and lacks a lot of the facts. It is a rare condition that affects only a small percentage of daily users. It is very unpleasant, but not dangerous except for dehydration. The belief is that it is a metabolite (breakdown product) of either THC or other cannabinoids that when it reaches a certain level in the body triggers a response from the emesis (vomitting) reflex center in the back of the brain. Since cannabis is an anti-nausea medicine, people can actually feel better at first when they smoke but later get worse when the active chemicals break down in the body. Since these are all fat soluble and can build up in the body's fatty tissue it takes a long time for the levels to drop down again and for the symptoms to subside. I usually expect patients I admit to the hospital to need about 3 days of IV fluids and anti-nausea medication before they can start to keep enough fluids down to go home. Often doctors just tell the patient to stop smoking and don't explain how the process works. The patient then tries to smoke a bit when they get home and feel better so they start the process all over again. I have seen the same patient admitted 3 or 4 times for the same problem because of this. Not every daily user gets CHS, but the rare ones who do will continue to get it if they use enough without a break to let the metabolites reach a toxic level again. Every patient I have cared for with this does get relief from hot showers or baths. The theory is that the temperature regulating area of the brain (in the hypothalamus) sits right next to the emesis center and by stimulating this, it over-rides the signal from the emesis center. If someone has symptoms like CHS but no relief from hot showers we start to look for other causes. Sorry for the science lesson but there is a lot of mis-information about this syndrome and the press seems to be using it as a way to scare people about Marijuana. When was the last time you saw an article in the paper about the dangerous effects of tobacco or alcohol. Everyone knows that if you drink heavily every day you will most likely DIE eventually of liver disease and that if you use tobacco every day you will probably die younger than you should from cancer or heart disease. Cannabis is one of the safest alternatives to these and other drugs like opiates, so to sensationalize a very rare (although unpleasant) side effect does everyone a dis-service.