The outer ear, the middle ear, or the inner ear. Inner ear infections are almost always viral. It is very unusual to have a bacterial infection of your inner ear.
Viral inner ear infections can effect either the organ of hearing or the organ of balance. When the organ of hearing is affected, the infection will usually present as a sudden hearing loss. It will not present with pain. In addition to hearing loss, it may cause a ringing noise in the ear, which we call tinnitus, or a sense of fullness or distortion.
Viral infections of the organ of balance present as imbalance or vertigo. Vertigo is the false sensation of motion, such as the room spinning or the floor rocking.
Occasionally viral infections of the inner ear will effect both the organ of hearing and the organ of balance and the individual might present with hearing loss, tinnitus or ringing in their ear, and dizziness, all at the same time.
The treatment for viral infections of the inner ear is usually oral steroids such as Prednisone, if there are no contraindications. In other words, if you don't have a disease which might be made worse by the Prednisone.
Inner ear infections are generally viral, and they can effect either the organ of hearing, or the organ of balance, or both. If they effect the organ of hearing, they will cause hearing loss, and if they effect the organ of balance, they will cause dizziness.