First, the baby suffering from a cold. Because a cold will reduce the resistance of the nasal mucosa, and the symptoms of a cold (stuffy nose, runny nose, etc.) will make the baby make actions that directly hurt the nasal mucosa (such as blowing your nose hard and picking your nose, etc.).
Second, the baby with allergic rhinitis. Because the nose is uncomfortable, the baby will often dig his nose and hurt the nasal mucosa.
Third, the baby who likes to pick his nostrils. Because of the frequent digging of the nostrils, the entrance to the nose and the vestibule of the nose are repeatedly injured. After scabbing, they will be stained with booger, and they will be dug involuntarily, forming a vicious circle. Over time, the entrance to the nose and the vestibule will fester.
Fourth, babies with blood diseases. Although this baby's nose is not injured, it often bleeds, usually with slow flow rate and frequent times. This type of nosebleed, you must take your baby to the hospital for a blood test immediately.