The causes of fever and spitting up include: 1. Infection is a common cause of fever and spitting up in babies. The child’s own immunity is low, and it is easy to induce infections after the change of season or the change of the environmental temperature, including upper respiratory tract infections, urinary tract infections, etc. The child may have a fever and spitting up after the change of season or the change of the environmental temperature. The child’s condition progresses quickly when the infection occurs, and it is easy to cause a systemic inflammatory response, resulting in fever, spitting up, and may even have viral encephalitis, convulsions, and other symptoms occurring one after another. When the systemic inflammatory response occurs, the child’s digestive tract function will be reduced, metabolism slowed down, easy to spit up and fever at the same time, if the child’s body temperature is too high, poor mental state, the need to go to a specialist hospital in time to avoid delay. 2, indigestion leads to abdominal distension, accumulation of food, fever, spitting up, etc., serious indigestion in addition to gastrointestinal dysfunction, but also systemic reaction! Severe dyspepsia, in addition to gastrointestinal dysfunction, will also have systemic reactions, such as fever, nausea, constipation and poor mental status.