I would think you would have to try really hard to hold your breath against the pressure..and why would you?
Actually, in normal condition (mental & physical) it's
imposible for you to hold your breath
(intentionally close epiglotis) agaist pressure to the point of lung overexpansion, at least for untrained people. If you know how to pack your lung (in freediving), you will see that just a small increase of pressure will make you caugh to open the epiglotis.
But unfortunately, if your
epiglotis is closed unintentionally in a terrible condition, eg. panic, scared, inhaling water, etc, or if your
airway is obstructed as a result of sickness or anything else, then in combination with a fast ascent your lung (alveoli) will most surely to be "bursted"!
As a diver in general, my first enemy is panic, and I never dive in bad condition (mental, physical, weather). As a scuba diver, I never ascend fast, never look down on lung overexpansion nor DCS, but hold my breath all the time! As a freediver and a scientist, I oppose both scuba rule "
never hold your breath" and freediving rule "
never inhale compressed air at depth." The "common wisdom at the time" (actually the common stupidity of the time) that "
if a freediver inhale compressed air at depth, his/her lung will be bursted" did kill the beautiful freediver Audrey Mestre in the same year this thread was started, 2002, and just 1 month 1 day after the last post by Dr. Thomas!!!
In conclusion, lung
overexpansion (pulmonary barotrauma) is not a myth, no way! But its cause is
not "breath holding". I will post video clip of my demo of inhaling compressed air at depth (10 metres) then ascend breath holding. Anyone want to see if my lung bursts, just stay tune...
Sincerely
