A baby’s belly button bulging out may be caused by physiological reasons, or may be caused by pathological reasons. If it is caused by pathologic reasons, it is necessary to timely treatment such as umbilical hernia belt pressure, surgery and so on. 1. Physiological reasons When the baby is emotional (such as crying, fussing, etc.), the pressure in the abdominal cavity may rise, and the baby’s belly button may bulge out. In addition to emotional abnormalities, straining to pass stools may also be a cause. If it is caused by the above reasons, when the baby is emotionally stabilized or after defecation, the bulging belly button can mostly return by itself, so there is no need to worry too much. 2. Pathologic causes: There are a number of diseases that may cause an increase in abdominal pressure, allowing the baby’s belly button to bulge out, called an umbilical hernia. Umbilical hernia is a common disorder of the umbilicus that occurs most often in infants and young children. The hernia sac can protrude through the umbilical ring, causing the infant’s belly button to bulge out, and the protrusion of the belly button can worsen when coughing or crying and lessen when lying down. If an umbilical hernia is causing your baby’s belly button to bulge out, you will need to go to the hospital to receive treatment for your baby’s umbilical hernia. Neonatal umbilical hernias are usually treated with surgery, while umbilical hernias in infants and young children are treated with non-surgical treatments, such as the use of umbilical hernia straps to apply pressure and immobilize the umbilical hernia. The specific treatment plan should be decided by the doctor according to the condition. It is recommended to bring your baby to the hospital as soon as possible to check the cause of the hernia.