“Cannabis acts a temporary bronchodilator rather than a bronchoconstrictor”. Cannabis has been shown to open the airways of asthmatics when one is having an asthma attack. Cannabis also has proven to be an anti-inflammatory agent and pain-relieving. Therefore, while one’s lungs are inflamed(awake or asleep), they can be more comfortable because CBD makes it so. Surprisingly, cannabis smoke doesn’t have the same toxins as cigarettes so that means one consuming CBD won’t have to be concerned about damaging their lungs in the process.
“Cannabis and asthma? You might be surprised at what happens when you combine the two…”
https://www.green-flower.com/articles/322/how-cannabis-treats-asthma