The movement of these bones sends sound waves across the middle ear to the inner ear. The inner ear sends the sound messages to the brain. But if the middle ear has fluid in it, then the eardrum and the bones cannot move well. This could cause your child to have trouble hearing. If your child has middle ear fluid, it means that a watery or mucous-like fluid has collected behind the eardrum.
Many children get middle ear fluid during their early years.
But middle ear fluid is not the same as an ear infection. An ear infection may occur in one or both ears. With a middle ear infection your child may have fever and sharp ear pain. When your health care provider looks into your child's ear, they might see a bulging red eardrum and some fluid in the middle ear. Middle ear fluid may be found in one or both ears.