barcsimalsi wrote:How can the breath be injurious or non-injurious? Can it be something like smoking marijuana?
I think it depends on how one breathes and with what intention.
culaavuso wrote:Most breathing does not cause injury. It seems rather rare for breathing to cause injury, though it could happen in cases such as taking a rapid deep breath with a freshly broken rib or hyperventilating when trapped in an area with limited air supply or deeply inhaling noxious fumes.
Breathing can be injurious not just in the cases you mention.
It's easily enough possible to get oneself upset simply by the way one breathes (such as by staccato shallow breaths). It is possible to cultivate passion and lust simply from the way one breathes (such as by breathing deeply and quickly, and holding on a bit before the outbreath).
Then there is the case where a person's heart takes up the pace of an external sound/noise. If one goes to a rave party, one's heart may pick up the pace of that music. With it, the breathing pace can change too.
Then there are people who tend to pick up the breathing pace of whoever they happen to be with. For example, I tend to pick up the breathing pace of my cat. She breathes at a pace about one and a half time faster than I normally would, and following her makes me dizzy, tense, and irritated. It takes me conscious effort to attend to my breath when in the presence of my purring cat, or I feel uncomfortable (so much for "snuggling comfortably").
(Although the exact breathing modes for the arising of these mental states may vary from person to person.)