Eustachian Tube Dysfunction
What is the eustachian tube and what does it do?
The Eustachian tube is a narrow tube that connects the middle ear space with the back of the nose. In adults it is about 3-4 cm long. The middle ear space is normally filled with air. The air in the middle ear is constantly being absorbed by the cells that line the middle ear and fresh supplies of air are routed to the middle ear via the eustachian tube.
The Eustachian tube is normally closed but opens from time to time when we swallow yawn or chew. This allows air to flow into the middle ear and any mucus to flow out. This also keeps the air pressure equal on either side of the eardrum. Having equal air pressure on each side of the eardrum and keeping the middle ear free of mucus enables the eardrum to work and vibrate properly, resulting in normal hearing.
What is Eustachian Tube Dysfunction (ETD)?
Eustachian tube dysfunction (ETD) is a condition where the Eustachian tube is blocked or does not open properly. Air cannot then get into the middle ear, leading to a pressure differential between the the outer side of the eardrum becomes and the air pressure in the middle ear. This pushes the eardrum inward. The eardrum becomes tense and does not vibrate so well when hit by sound waves, resulting in a sensation of decreased hearing.
What are the symptoms of Eustachian Tube dysfunction?
The main symptom is muffled or dulled hearing, similar to what is experienced when an aeroplane is ascending or descending. There may also be ear pain as the eardrum is tensed and stretched. Other symptoms that may also develop include: a feeling of fullness in the ear; tinnitus (ringing or buzzing in the ear); dizziness. One or both ears may be affected.
Symptoms can last from a few hours to several weeks or more, depending on the cause. As symptoms are easing there may be popping sensations or noises in the ear. In addition, the muffled hearing may come and go for a short time before getting fully back to normal.
What are some causes of Eustachian Tube Dysfunction?
ETD occurs if the Eustachian tube becomes blocked, if the lining of the tube becomes swollen or if the tube does not open as it should to allow air to travel to the middle ear space. Some common causes include:
Upper respiratory tract infections
This is the most common cause of ETD. The thick mucus that develops during a cold or other infections may block the Eustachian tube outlet. An infection may also cause the lining of the Eustachian tube to become inflamed and swollen. Most people will have had one or more episodes in their life when they have had a cold and find that they cannot hear so well due to ETD. These symptoms of ETD may persist for up to a week or so (sometimes longer) after the other symptoms of the infection have gone as the trapped mucus and swelling may take time to clear.
Allergies that affect the nose such as allergic rhinitis and hay fever can cause extra mucus and inflammation in and around the Eustachian tube, and lead to ETD.
Anything that obstructs the Eustachian tube can cause ETD. These include enlarged adenoids, and in some rare cases, tumors of the back of the nose.
How does air travel affect the eustachian tube?
Some people develop ear pain when the plane descends to land. This is caused by unequal pressure that develop on either side of the eardrum as the plane descends.
As a plane descends the air pressure becomes higher nearer the ground. This pushes the eardrum inwards which can be painful. In most people just normal swallowing and chewing quickly cause air to travel up the Eustachian tube to equalise the pressure.
How is Eustachian Tube Dysfunction Treated?
Often no treatment is needed – especially after a upper respiratory tract infection, the ETD is mild and does not last longer than a few days or a week or so. Some conservative treatments can be attempted, as follows:
Try to get air to flow into the Eustachian tube
Air is more likely to flow in and out of the Eustachian tube if you swallow, yawn or chew. The Valsalva maneuver may also be performed, as follows: Take a breath in. Then try to breathe out gently out through your nose with your mouth closed and with the nostrils pinched at the same time. In this way, no air is blown out of the nose or mouth, but air is being pushed into the Eustachian tube into the middle ear space. If you do this you may feel your ears go ‘pop’ as air is forced into the middle ear. This sometimes eases the problem. This can be repeated as many times as necessary, without fear of damaging the eardrum.
Antihistamine tablets / Intranasal steroid sprays
In cases of ETD secondary to allergies, these, will help to ease nasal congestion, inflammation and amount of mucus production.
If conservative treatment fails, there are surgical options. A catheter can be used to insert a small balloon through the nose and into the Eustachian tube. The balloon is then inflated, opening up (dilating) a pathway for mucus and air to flow more normally, helping to restore proper Eustachian tube function. The balloon is deflated and after dilation and then removed.