Nausea is controlled by a part of the central nervous system that controls involuntary body functions (like the heart beating). Vomiting is a reflex controlled by a vomiting center in the brain. Vomiting can be triggered by smell, taste, anxiety, pain, motion, poor blood flow, irritation, or changes in the body caused by inflammation.
The most common causes of nausea and vomiting are:
Nausea and vomiting are more likely if the patient: