Nausea

Nausea is not an illness in itself; it is rather a possible symptom of several conditions, many of which are not related to the stomach at all. In fact, more often than not nausea indicates a condition somewhere else in the body rather than in the stomach itself. An example of this is travel sickness, which is due to confusion between perceived movement and actual movement. Our sense of equilibrium lies in the ear and works together with eyesight. When these two don't "agree" to what extent the body is actually moving the symptom is presented as nausea even though the stomach itself has nothing to do with the situation. Nausea is also an adverse effect of many drugs.

In medicine, nausea is a particular problem during some chemotherapy regimens and following general anaesthesia. Nausea is also a common symptom of pregnancy. Even though nausea is generally seen as an indication that something is wrong, experiencing it during pregnancy is quite normal, and should not be considered an immediate cause for alarm.