Refer to figure.

OTIC BAROTRAUMA

Pressure is normally equalized across the eardrum by the eustachian tube leading from the middle ear to the back of the mouth/nose. If the eustachian tube is blocked, air cannot reach the middle ear, so the pressure there decreases. When air pressure is lower in the middle ear than in the ear canal, the eardrum bulges inward. The pressure difference can cause pain and can bruise or rupture the eardrum.

• The problem is increased if the person has a cold or any other condition which has caused the mucous membrane lining the eustachian tube to become inflamed and swell. Someone with a cold will probably not be able to equalise the pressures and is at increased risk of Barotrauma.

SINUS BAROTRUMA

The sinuses are small, empty spaces behind your cheekbones and forehead that connect to the inside of the nose. During ascent and descent, gas flows freely out of and into the sinuses. In the presence of inflammation of the lining of these sinuses, as in sinusitis or with a severe head cold, swelling may obstruct the outlets. This will cause pain, which can be severe, during a descent.