A doctor will diagnose a middle ear infections by doing a physical exam and an ear exam and by asking questions about past health.

The doctor uses a tool called a pneumatic otoscope to look at the eardrum for signs of an ear infection or fluid buildup. For example, the doctor can see if the eardrum moves freely when the otoscope pushes air into the ear.

This exam is rarely uncomfortable. It bothers some children more than others.

Other tests may include:

• Hearing tests. These tests are recommended for children who have had fluid in one or both ears (otitis media with effusion) for a total of 3 months. The tests may be done sooner if hearing loss is suspected.
• Tympanometry. It measures how the eardrum responds to a change of air pressure inside the ear.
• Tympanocentesis. This test can remove fluid if it has stayed behind the eardrum (chronic otitis media with effusion) or if infection continues even with antibiotics.
• Blood tests. These are done if there are signs of immune problems.