Outer Ear Barotraumas can occur when the ear canal becomes blocked, trapping air between the blockage and the ear drum. This can create excess pressure or a vacuum in the air space as the diver changes depths. Blockages can be caused by excess wax, non-vented ear plugs or an extremely tight fitting hood. Due to the increasing pressure and squeeze in the outer-ear, the surrounding tissues can fill the canal with blood and fluid or the eardrum can rupture. Pain and discomfort will be noticed and after a release of pressure (due to the eardrum rupture), the cold water entering the middle ear may lead to vertigo.