Hi there-

I'm asthmatic and on singulair pills and advair inhaler daily. I have had a PFT in the past.

It's painless They basically have you breathing into a tube and it measures your lung capacity. They will also make you like hyperventilate at one point and you'll feel a bit dizzy but it's not bad. They then give you a puff of an inhaler to measure your capacity again.

I think it takes about 45 min to an hour.

Good luck!
Tranquility