Vomiting during breastfeeding can be caused by pregnancy, acute gastroenteritis and indigestion. 1. Pregnancy: It is also possible for a woman to ovulate while she is breastfeeding. If you don’t pay attention to proper contraception, it may lead to another pregnancy without your knowledge. After pregnancy, the early pregnancy reaction will cause nausea and vomiting and other uncomfortable symptoms. 2. Acute gastroenteritis: during the breastfeeding period, if a mother eats unfresh food or is infected with bacteria or viruses, it will easily cause acute gastroenteritis, resulting in nausea, vomiting, abdominal pain, diarrhea and other uncomfortable symptoms. 3. Indigestion: If a woman eats too much indigestible food after giving birth, it will easily lead to digestive disorders of the gastrointestinal tract, resulting in indigestion, such as abdominal pain, bloating, nausea, vomiting, etc. It is recommended that if a woman has symptoms of indigestion after giving birth, she should be advised to take care of herself. It is recommended that mothers who experience any special discomfort after giving birth should go to the hospital as soon as possible.