Eustachian tube patency
Eustachian tube patency refers to how much the eustachian tube is open. The eustachian tube runs between the middle ear and the throat. It controls the pressure behind the eardrum in the middle ear space. This helps keep the middle ear free of fluid.
The eustachian tube is normally open, or patent. However, some conditions can increase pressure in the ear such as:
- Ear infections
- Upper respiratory infections
- Altitude changes
These can cause the eustachian tube to become blocked. Alternatively, if the eustachian tube becomes blocked first, the pressure in the middle ear will go up and fluid may accumulate in it.

The ear consists of external, middle, and inner structures. The eardrum and the 3 tiny bones conduct sound from the eardrum to the cochlea.

The eustachian tube is the tube that runs between the middle ear and pharynx and regulates the ear pressure around the ear drum.
References
O'Reilly RC, Levi J. Anatomy and physiology of the eustachian tube. In: Flint PW, Francis HW, Haughey BH, et al, eds. Cummings Otolaryngology: Head and Neck Surgery. 7th ed. Philadelphia, PA: Elsevier; 2021:chap 130.
Player B. Otitis media. In: Kliegman RM, St. Geme JW, Blum NJ, et al, eds. Nelson Textbook of Pediatrics. 22nd ed. Philadelphia, PA: Elsevier; 2025:chap 680.
Version Info
Last reviewed on: 7/16/2024
Reviewed by: Neil K. Kaneshiro, MD, MHA, Clinical Professor of Pediatrics, University of Washington School of Medicine, Seattle, WA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
