Ménière's disease turn, is strongly associated with developing MD, but not everyone with EH develops MD: "The relationship between endolymphatic hydrops and Meniere's disease is not a simple, ideal correlation." Additionally, in fully developed MD the balance system (vestibular system) and the hearing system (cochlea) of the inner ear are affected, but there are cases where EH affects only one of the two systems strong enough to cause symptoms. The corresponding subtypes of MD are called "vestibular MD", showing symptoms of vertigo, and "cochlear MD", showing symptoms of hearing loss and tinnitus. The mechanism of MD is not fully explained by EH,
Ear clearing the common cold, as this may cause what is known as a reverse block. Descent is uninhibited as the Valsalva maneuver may still clear the eustachian tubes temporarily by force, but during ascent a blockage may stop the air in the middle ear (which is now at depth pressure) from escaping as the diver ascends. The eardrum then bursts outwards, causing the same hazards as with an ordinary burst eardrum, such as cold water in the middle ear deranging the working of the sense organs of balance in the inner ear. Nasal congestion may affect the sinus openings and the