Two and a half months baby suddenly very sleepy, may be physiological factors, infectious diseases, physiological factors generally do not need to be treated, disease factors need to be treated for the cause. 1. Physiological factors: mostly due to the baby play too tired, get up too early in the morning, sleep deprivation, etc., is a normal physiological phenomenon, generally ensure adequate sleep. 2. Infectious diseases: mostly due to the baby cold and fever, infectious diarrhea and other diseases caused by the baby’s physical weakness. If it is a viral infection, generally can be self-healing, do not need special medication; if the combination of bacterial infection, need to eat amoxicillin and other antibiotics. Fever, if low, can be lowered by warm water wiping, reducing clothing and so on. The above drugs in use, must be strictly in accordance with the doctor’s instructions under the guidance of the doctor to take. 2.5 months baby suddenly very sleepy may also have other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, to give targeted treatment or treatment.