Hiccups in infants are caused by certain causes, such as irritation of the diaphragm or excess air in the stomach, and normally do not occur often. Hiccups are also more common in infants and children whose diaphragms are not particularly well developed, such as when an infant suddenly inhales colder air, which stimulates the diaphragm to contract in spasm. This can be relieved by keeping the baby out of cold places, raising the room temperature, and keeping the child warm. Another cause of hiccups in babies is improper posture when drinking milk, inhalation of a lot of air, and over-eating. Back patting can be used to relieve hiccups, which usually stop when the excess gas is removed from the stomach. Some babies also have hiccups because they are allergic to certain ingredients in formula such as milk proteins, and the condition is usually characterized by frequent hiccups after drinking milk. For such babies, it may be necessary to consult a doctor and choose a special formula that is hypoallergenic. Hiccups are relatively normal and can be relieved by a number of methods, usually due to cold air or allergies to certain substances.