One-third of these youngsters will have repeated bouts of ear infections. Most ear infections don't lead to permanent hearing loss. Some infections that aren't treated, however, can spread to other parts of the ear, including the inner ear. Infections of the middle ear can damage the eardrum, ear bones and inner ear structure, causing permanent hearing loss. An ear infection often begins with a respiratory infection such as a cold.
Colds cause swelling and inflammation in the sinuses and eustachian tubes.
Children's eustachian tubes are shorter and narrower than adults. This size makes it more likely that inflammation will block the tube completely, trapping fluid in the middle ear. This trapped fluid causes discomfort and creates an ideal environment for bacteria to grow. The result is a middle ear infection. Bacteria cause most ear infections.