I've never gotten a full diagnosis on what kind of asthma or what the cause is, but I've had it since middle school, and it's mostly triggered by activity. I was hoping this would help me out spiritually but also with the breathing, because I have trouble working out due to it (and I feel we're approaching a time where being fit is important). But it's breathing, it's just quick breathing, and it's not much breathing..and I have no idea if or how it'll help.
"Life is in the breath," that's why I have started doing it anyways.
Astma is a form of dampness, same as other forms of congestion. The airways are swollen/congested, causing difficulty breathing.
This can be seen as a form of harmful Yin build up in the lungs and airways.
The breath of fire technique generates Yang energy, which burns up the poisonous Yin and purifies it, clearing/evaporating the dampness and opening the congested airways over time.
I believe this is a big part of the underlying principle and why it works to heal astma.
Smoke damage to the lungs is also in the form of Yin poisoning, the resulting shortness of breath and tightening of airways that long term smokers experience is very similar to astma is that regard, and can be cleared out too with natural breath of fire, but smoke damage causes dryness as well, so you would need to use both dampness and fire to heal the lungs, to evaporate and clear the toxins and tar that have build up in the lungs in that case.
The latter is often why long term smokers experience some relief when they switch to vaping from smoking, because the vape is very damp and wet, helping in the short term to clear out some tar and toxins, but it is not a cure.