Nausea, the sensation of having the urge to vomit, and vomiting, the emptying of the contents of the stomach through the mouth, may be caused by a variety of different reasons. Some common causes of nausea and vomiting are:
Gastroenteritis, commonly known as stomach flu, from bacterial or viral infections
Food poisoning
Overeating
Migraine headaches
Brain injury or concussions
Inner ear and balance disorders
Motion sickness
Hormonal imbalances, especially during the first trimester of pregnancy
Certain toxins, such as alcohol
Drugs, such as chemotherapy agents, for treating cancer
