Is Prolonged Expiration With Mild Asthma Symptoms Normal?


Asked by nscangal

Is Prolonged Expiration With Mild Asthma Symptoms Normal?

I've noticed that most of the time, when I'm short of breath, I also have difficulty getting all my air out (prolonged expiration). This can happen with no other asthma symptoms other than the shortness of breath (which can be very mild, even). Usually, it occurs on a windy, sunny, warm day (so I think pollen has something to do with it). Is it normal to have significantly prolonged expiration (I timed it and even trying to force the air out, it took me more than three times as long to exhale as to inhale, and normally it takes me about as long to exhale as to inhale) when the rest of your asthma symptoms are mild or not present at all, or is this something I should bring up with my doctor and/or respiratory therapist (I see an RT at my asthma clinic)?

Incidentally, this is not something new, but rather something that I've been curious about for a while. It happened again this morning and I took my inhaler because I was quite short of breath that time, but it prompted me to ask since I hate not knowing.


A normal i:e ratio (inspiratory to expiratory ratio) is 1:2 (as you can see here). You should ideally be breathing out twice as long as you are inhaling. A prolonged expiration is usually indicative of some sort of airway obstruction, however mild or severe. Normally expiration should be completely passive, meaning it requires no muscle effort. If you are finding that you have to work to exhale, this is a sign of worsening asthma or severe asthma.

I've actually had similar experiences when exposed to my asthma triggers, where I feel as though I can exhale "passively" forever and yet have no other asthma symptoms. This is actually one of my early signs of asthma for me, and a sign I need to stop whatever it is I'm doing and treat my asthma according to my asthma action plan. Perhaps the same is true with you.

Answered by John Bottrell