Nausea (Latin: Nausea, from Greek: Ναυτεία, “sea-sickness”, also called wamble) is the sensation of unease and discomfort in the stomach with an urge to vomit. Nausea is also an adverse effect of many drugs, opiates in particular, and may also be a side-effect of a large intake of sugary foods.
Nausea is not a sickness, but rather a symptom of several conditions, many of which are unrelated to the stomach. Nausea is often indicative of an underlying condition elsewhere in the body. Motion sickness, which is due to confusion between perceived movement and actual movement, is an example: the sense of equilibrium lies in the ear and works together with eyesight. When these two “disagree” about the extent to which the body is actually moving, the symptom is presented as nausea, although the stomach itself has nothing to do with the situation. The stomach’s involvement comes from the brain’s conclusion that one of the senses is hallucinating due to poison ingestion; the brain then induces vomiting to clear the supposed toxin.
In medicine, nausea can be a problem during some chemotherapy regimens and following general anesthesia. Nausea is also a common symptom of pregnancy, in which it is called “morning sickness”. Mild nausea experienced during pregnancy can be normal, and should not be considered an immediate cause for alarm.
When ingested or inhaled, marijuana has been shown to reduce nausea in the majority of users.