The eardrum is also known as the tympanic membrane. It is a thin layer of skin-like tissue which covers the end of the ear canal. It is a couple of centimetres in from the outer opening. The drum is delicate because it needs to be sensitive to tiny vibrations in order that we can hear quiet sounds. As a result, it doesn't take much force to cause it to rupture. Thankfully it is well protected from mechanical damage as it is situated in the ear canal.
What Causes A Burst Ear Drum? The two commonest causes of eardrum rupture are
- Ear infections
- Changes in pressure
How Do Ear Infections Cause Eardrum Rupture?
Ear infections cause eardrum through changing the pressure in the ear, so could be included in the second category. The Eustachian tube drains the space in the middle ear into the nasal cavity. Blockage occurs due to inflammation and infection in the nose and nearby areas. As a result the middle ear space fills with water which becomes infected and increases the pressure on the eardrum. This eventually ruptures.
What Is Barotrauma?
The second cause of rupture; changes in pressure, is also known as barotrauma. This occurs with with very loud noises, bomb blasts and with rapid changes in altitude or with water pressure at depth whilst scuba diving. Pressure changes occur whilst scuba diving and with altitude. These are usually compensated for by the Eustachian tube allowing the pressure to equalise on either side of the eardrum. This doesn't occur if the person has a cold or other ear infection, making eardrum rupture much more likely. Ear plugs may help prevent ear infections from scuba diving but should only be used in shallow water as they may cause damage at depth.