What causes sudden nausea?

Sudden nausea and vomiting may be caused by the patient eating a large amount of unclean and mildewed food, resulting in the gastrointestinal tract of the body being infected by bacteria, causing acute gastroenteritis, and sudden nausea and vomiting caused by inflammatory factor stimulation; it may also be caused by sudden nausea and vomiting caused by pregnancy of women, increased human chorionic gonadotropin levels in the body, and stimulation of gastrointestinal tract; When the patient's gastrointestinal dynamics are abnormal, visceral sensitivity is increased, and the central nervous system is disturbed, resulting in irritable bowel syndrome, sudden nausea and vomiting will also occur.