Nausea generally refers to nausea and vomiting, which may be caused by a variety of factors such as pregnancy reaction, emotional stress, duodenal ulcer, chronic pharyngitis, hypertension and so on. 1. pregnancy reaction: women of childbearing age early pregnancy due to hormonal changes in the body, some people will have a more significant pregnancy reaction, mainly manifested as nausea and vomiting, loss of appetite, and so on. 2. Emotional tension: encounter large-scale examination and other emotional tension, autonomic nerve stimulation of gastric mucosa smooth muscle spasm contraction, nausea and vomiting may occur, in addition may also be accompanied by panic and other symptoms. 3. duodenal ulcer: due to inflammation, gastric acid and other stimulation of the gastric mucosa, nausea, vomiting may occur, often accompanied by regular abdominal pain. 4. Chronic pharyngitis: chronic pharyngitis due to the inflammatory response to the secretion of viscous fluid, difficult to cough up or swallow, nausea and vomiting. 5. Hypertension: Hypertension may cause nausea and vomiting due to increased intracranial pressure and stimulation of the central nervous system. Excluding pregnancy and other physiological reasons, frequent nausea, should promptly consult a doctor to identify the causes under the guidance of the doctor, and reasonable treatment, so as not to delay the condition.