The baby sleepy after fever, considering that may be a common reaction after fever, may also be dehydration, electrolyte imbalance and other factors triggered. 1. common reaction after fever, the baby sleepy after fever because the body energy consumption after fever, the body is relatively weak, so this symptom may occur, is a common reaction. 2. Dehydration, the baby’s body water loss in the process of fever, dehydration symptoms may lead to the baby sleepy. 3. electrolyte imbalance, some of the baby electrolyte imbalance after the body metabolic abnormalities, may have an impact on the baby’s body, so there will be fever after sleepy symptoms. The baby sleepy after fever, there may be other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.