While anyone can get an ear infection, they are far more common in infants and children. They occur most often in infants between ages six months and eighteen months and are still quite common in children up to age four. By age seven, ear infections are pretty uncommon.

In addition to age, several other factors increase the risk of an ear infection. Children who are in group child care settings are more likely to get ear infections because they are exposed to more germs than children who stay at home. Babies who drink from a bottle while lying down are more prone to ear infections than those who eat while held upright. Poor air quality is also a risk factor for ear infections: children who have tobacco smoke or pollution in their environment experience more ear infections. Ear infections also tend to be most common during the fall and winter months, when colds are more common.

American Indians and Eskimos/Inuit from Alaska or Canada tend to have more ear infections than Caucasians do. Ear infections also occur more commonly in boys than girls.

A final risk factor for ear infections is family history. If a family member has or had ear infections, you or your child is more prone to getting them. This could be due to several genetic factors, but the most important may be having Eustachian tubes that do not work as well as they should. This makes the build-up of fluid in the middle ear more likely and makes ear infections more common.