Spitting up from breastfeeding may be related to physiological structure, improper feeding, medical diseases, surgical diseases and other factors. 1. Physiological structure: Infants have a small stomach that is in a horizontal position, which may lead to spitting up if they are overfed or if they swallow too much air. 2. Improper feeding: Parents who breastfeed their babies in an incorrect position may also experience the above situation. 3. Medical diseases: Babies with medical diseases such as gastroesophageal reflux, pancreatic spasm, constipation, intracranial hypertension, etc. may also vomit. 4. Surgical diseases: infants with surgical diseases such as esophageal atresia, congenital megacolon, intussusception, etc., may also experience the above symptoms. There may be other reasons for babies to vomit from breast milk, it is recommended to bring babies to the hospital in time for relevant examinations to clarify the cause of the disease and then actively treat the symptoms.