Baby crying after vaccination may be caused by local pain, gastrointestinal discomfort, fever and other reasons. 1. Localized pain: due to the vaccination, local damage can occur, and the components of the vaccine can also stimulate the local. The child may experience redness, swelling, heat and pain, which may cause the baby to cry. 2. gastrointestinal discomfort: after vaccination due to the adverse reaction of the vaccine can appear the phenomenon of decreased digestive ability, there will be diarrhea, abdominal pain and so on. The baby cries in order to express the discomfort. 3. Fever: After vaccination, the baby’s immune system may react to the vaccine and develop fever. At this time, the baby may have a headache and other symptoms, resulting in the phenomenon of crying. Crying after vaccination may also be caused by other reasons, it is recommended that patients should go to the hospital in a timely manner, follow the doctor’s instructions for treatment, to avoid delaying the condition.