The Eustachian tube (ET) connects the middle ear (the space immediately behind the eardrum) with the back of the nose/throat. Its opening and closing serve to equalize pressure on both sides of the eardrum, and to protect the middle ear. ET dysfunction (ETD) can cause a variety of middle ear problems, including hearing loss. Diagnosis of ETD may be based on a combination of a patient’s history, physical examination, and sometimes tests or imaging. An otolaryngologist may offer a variety of treatments, from medical (oral or nasal decongestants) to surgical (balloon dilation, laser coagulation).