Why is it always nausea? What's going on?

Nausea and vomiting may be caused by digestive system problems such as indigestion, chronic gastritis, etc., or liver diseases such as hepatitis, cirrhosis, etc., which can cause gastrointestinal symptoms. In addition, if it is a woman of childbearing age, in the case of sexual life, it can be considered as pregnancy caused by early pregnancy symptoms.