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Timothy C. Hain, MD
Page last modified:
January 5, 2008
The Eustachian tube (ET) connects the air filled middle ear space to the throat. It's function is mainly to keep the pressure in the middle ear equalized with pressure in the outside. When the pressure becomes negative with respect to the outside world, the ear drum gets pulled inward. When pressure is positive, the ear drum bows outward.
A valve near the opening into the middle ear allows controls this process. The valve is usually closed, which keeps bacteria and various other things in the mouth and nose from getting into the middle ear. It opens naturally when there is a big pressure difference between the middle ear and nose (such as when you blow your nose). It often can be opened by yawning, opening the mouth widely, and swallowing. Some talented people can open it voluntarily.
When it cannot be opened easily, pressure differentials build up. Usually this results in a "full" feeling -- whether the ear is over or under-pressurized with respect to the outside world. There are other causes of "full" feelings -- such as Meniere's disease, but this is the only one that responds to "popping" of the ear.
Inability to pop the ears can be a problem in persons who fly on airplanes and who Scuba dive. More about ET dysfunction is here.
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Dr. Adam Politzer (from http://www.sld.cu/sitios/otorrino) |
You may have noticed that your ear pops when you blow your nose. Sometimes people learn or are taught how to blow pressure up into the middle ear. This is generally done by basically the same technique as blowing the nose, but the nose is pinched completely shut. Pressure created by blowing will often go upward into the ET, open the valve, and overpressurize the middle ear (notice that we didn't say that it normalizes pressure)
This is called "Self Politzerisation", after it's inventor, Dr. Adam Politzer. Dr. Politzer devoted most of his career to the ET. Amazingly enough, there is presently a society named after Dr. Politzer. This society is having an international meeting in October 2007, in Cleveland Ohio.
While generally, blowing the nose forcefully with the nostrils pinched shut or using the fancier name -- self-Politerization -- does not cause any harm, people who do this very frequently or use very high pressure can damage their ear drum. This can cause the ear drum to "sag", which reduces hearing and also alters ear test results (tympanometry).
Extremely rarely, people who create very high pressure differentials in their middle ear, perhaps by Scuba diving, can damage it by causing a fistula.
Eustachian tube function can be evaluated formally by the process of measuring pressure in the ear using tympanometry, documenting that it is different than 0, then having the person attempt to open up their ET, and then measuring it again. If pressure changes, then the ET opened. If it didn't, either the pressure was normal to start with, or the tube didn't open.
There are rare disorders where the ET opens regularly and periodically -- mainly palatal myoclonus. This is a fascinating condition where the palate moves up and down rhythmically, and is often accompanied by rhthmical oscillation of the ET too.
| © Copyright May 22, 2008 , Timothy C. Hain, M.D. All rights reserved. Last saved on May 22, 2008 |