Nausea is not a medical condition in and of itself, but rather a common symptom of everything from cancer to epilepsy to multiple sclerosis. Sometimes the disease itself causes extreme nausea, and sometimes vomiting is a reaction to the medicines or chemo therapy used to treat a chronic condition.
Cancer patients going through chemo are among the largest group of people routinely given cannabis to treat nausea. It has an added effect of increasing the appetite, to help keep them eating.
However, cannabis has been used to soothe another kind of nausea as well: the nausea associated with morning sickness.
While there are more conventional drugs that are often given to pregnant women with extreme cases of morning sickness, the fact that marijuana can be taken via nebulizer (vaporizer) means that it can bypass the GI tract and stay down.
Is marijuana safe for pregnant women and their babies, however? A study in Jamaica showed that there was no discernable difference between newborns or one-month old babies whose mothers had used marijuana during pregnancy and those whose mothers did not.
Even so, most of the time when cannabis is prescribed as an anti-emetic, it is done so to treat symptoms of chronic diseases.