Eustachian tube problems and the associated ear infections are some of the most common problems seen by doctors. Many people have chronic problems regulating middle ear pressure. Causes range from allergies to excessively small Eustachian tubes (as may afflict children with Down Syndrome). These patients often notice intermittent ear fullness, ear popping or cracking, mild hearing loss (an attenuation of sound), ringing in the ears (tinnitus), and/or occasional poor balance. Smoking is often associated with damage to the cilia that sweep along mucus and debris from the middle ear space to the back of the nose where it may be expelled.