My doctor says it is. I do the same. My 02 levels drop also when I walk especially up steps or even the smallest of an incline. Pursed lip breathing helps me.

.its the same in Ireland, u have to do a walking test.

It helps me also. In through the nose and blow until empty then start over. It really helps.

same thing with me breathe easy

I assume you mean an oxcimeter when you says meter? It sounds like you recover pretty quickly if you get short of breath? That is good! To get oxygen in the US you have to do a walking test for a permeant prescription I believe!