Vomiting is a relax that causes moving materials from stomach to the mouth via esophagus.Esophagus has peristaltic movement that sends foods from moth to stomach.In vomiting with anti-peristaltic movement of esophagus foods and liquid were returned to the mouth cavity. Control center of vomiting is in the brain and with depressing this center  vomiting can be prevented and with stimulation of it vomiting can be induced.Although vomiting can be occurred as a strong reflex of stomach to its material event when this center has been blocked with some medications.

Causes: vomiting can be done by inhalation or injection some chemicals or medications or eating some materials or even food.Theses materials can be chemicals like a poison or foreign body like a piece of plastic.In addition esophagus, liver, kidney and endocrine diseases, gastric or duodenum ulcer, gastrointestinal obstruction and some cancers cause vomiting.

To diagnose the reason of vomiting most often blood test, radiography and ultrasound from abdomen are necessary.