Eustachian tube patency describes a condition in which the eustachian tube is continually open. The eustachian tube is a structure in the ear that runs from behind the eardrum to the back part of the nasal cavity.

What is going on in the body?

Normally, the eustachian tube is closed at the back of the nasal cavity. It can open during swallowing or yawning to equal the air pressure on either side of the eardrum. In a eustachian tube patency, the canal is constantly open. As a result, there is greater chance of infections spreading into the middle ear space.

What are the causes and risks of the condition?

In most cases, the cause of eustachian tube patency is unclear. It is often seen in a person who has lost an excessive amount of weight. One theory is that the loss of fat tissue around the canal allows it to be constantly open. Other possible causes are radiation therapy and Down syndrome.