Nausea before menstruation mainly occurs when the sex hormone level in the body is in an unstable state before the onset of menstruation, sometimes with digestive symptoms such as nausea, regurgitation, and loss of appetite, which are symptoms related to PMS. Some women also experience headache, breast swelling, abdominal fullness, edema, anxiety, sleep disorders, lack of concentration and other symptoms, which also belong to PMS. Before the onset of menstruation, the diet should be light, small and frequent meals, avoiding the intake of greasy, fatty and fried foods, cold, spicy and stimulating foods, as well as hot pot, barbecue, seafood and other types of food should also be avoided. Eat more fresh vegetables and fruits, and pay attention to rest, avoid straining and staying up late. If the nausea and regurgitation symptoms are strong, you can take a small dose of vitamin B6 to regulate, which will help improve the symptoms.