The blue color on both sides of the baby’s nose may be related to normal physiological structure, trauma, lack of oxygen and other reasons. 1. Normal physiological structure: if the baby is less than six months, due to the thin subcutaneous fat, superficial veins are easy to show, can appear on both sides of the nose blue phenomenon. 2. Trauma: If the baby’s nose area is hit and other injuries, it can cause capillary rupture in the nose area to appear subcutaneous bruising, which can be manifested as blue on both sides of the nose. 3. lack of oxygen: if the baby suffers from congenital heart disease or pneumonia and other lung diseases, may cause the baby’s body lack of oxygen, may also appear the phenomenon of nose blue. Parents are advised to take their babies to regular hospitals in a timely manner to clarify the cause, and if treatment is needed, standardized treatment should be carried out under the guidance of the doctor to avoid delaying the condition.