The cause of hiccups is an unconscious spasm of the diaphragm, a large area of muscle located between the stomach and liver. During hiccups, the diaphragm spasms and contracts, forcing the person to take a deep breath in, while at the same time the vocal cords “snap” shut, making a hiccuping sound. Factors that may trigger hiccups in newborns: The diaphragm of newborns is immature, so the following factors may trigger hiccups in newborns: (1) Cold stomach: When the stomach gets cold, the diaphragm will contract involuntarily and react with hiccups. (2) Eating milk too quickly: Since the diaphragm is close to the stomach, the activity of the stomach often affects the diaphragm, and if the stomach expands too quickly, this can lead to spasm of the diaphragm and make the child hiccup. (3) Swallowing too much air while sucking milk: If a newborn baby does not pay attention to the nipple of the bottle or the areola when it is full, the baby will suck in too much air, which will also produce a hiccup reaction. (4) Feeding after baby cries: Hiccups are easily induced. (5) Milk that is too cold: giving your baby milk that is too cold and feeding too much cold medicine, which then interferes with the normal functioning of the spleen and stomach, can also trigger hiccups. (6) Liver below the diaphragm: frequent hiccups can also occur when there are lesions in the pancreas and gallbladder.