Phlegm during pregnancy is mostly seen in improper diet, in addition to increased secretion of stomach acid during pregnancy, respiratory system diseases, etc. may lead to excessive sputum secretion. I. Improper diet: If you eat too greasy or too sweet food during pregnancy, it is easy to have more phlegm, because sweet food stimulates the throat, which will make the secretion in the throat become sticky and increase. Second, increased secretion of stomach acid: after pregnancy, the body of pregnant women increased secretion of progesterone, affecting the gastrointestinal motility, resulting in increased secretion of stomach acid, some pregnant women may have reflux of stomach acid, which stimulates the throat, inducing inflammation of the throat, resulting in increased secretions in the throat. Third, respiratory diseases: 1, cold: cold stimulation or common viral infection after pregnancy will induce a cold, after the cold will appear more phlegm, cough, dry throat, runny nose and other symptoms; 2, chronic pharyngitis: pharyngitis is a chronic disease, and the same as the cold, a little inattention in life may recur, such as drinking less water, eat spicy and stimulating food, etc., it is easy to stimulate the pharynx, inducing pharyngitis. 3, rhinitis: some pregnant women have a history of rhinitis, rhinitis attacks may have postnasal drip, that is, there is snot flowing to the throat, will also stimulate the throat to appear increased secretions; 4, lung infection: some upper respiratory tract infection may develop downstream to pneumonia or bronchitis, inflammation stimulates the mucous membrane will appear increased secretions, manifested as increased sputum. In addition, it is necessary to distinguish whether it is respiratory secretions, also known as sputum, or saliva secreted by the mouth, and increased saliva during pregnancy is a normal physiological change.