Nausea that occurs due to improper diet, excessive mental stress, motion sickness, etc. usually does not require too much stress. If the nausea occurs frequently and is difficult to improve on its own, or even if frequent vomiting occurs, it may be a precursor to disease. To determine the diagnosis it is often necessary to consider it in combination with other symptoms, such as a digestive system problem if accompanied by abdominal distension, abdominal pain and other digestive manifestations, or a vestibular problem if accompanied by vertigo.