I'm At A Loss

[Lord Sorril]

since human and reptile lungs are not that different

They function similarly-very true. I wouldn't say that they aren't that different.
http://sksundstrom.wixsite.com/madag...ng-the-Systems

If your snake is in shed and not actually pale: I wouldn't spend the money on a Vet.
If you can't decide: you could post some pics and we could give you our opinion.